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Math, Science & Conversion Calculators

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🔢PercentageThree percentage questions in one tool 🔁Unit Conversion12 categories, exact factors shown 💯AverageMean, median, sum & count from any list 📅AgeFind an exact age between two dates ➗FractionAdd, subtract, multiply, divide with steps

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Unit Converters145

🪙Nickels to Dollars ConverterTurn a pile of nickels into dollars, bank rolls, and weight 💰Dimes to Dollars ConverterDimes to dollar value, $5 rolls, and weight 💵Quarters to Dollars ConverterQuarters to dollars, $10 rolls, and weight ⏱️Engine Hours to Miles ConverterEstimate equivalent miles from engine-hour readings ⛽Fuel Economy Converter (MPG ↔ L/100km)Convert MPG, L/100km, and km/L in any direction, US or UK gallons 💊mcg to IU ConverterMicrograms to International Units by nutrient (D, A, E)🥄mg to tsp ConverterMilligrams to teaspoons using substance density 🩸mmol/L to mg/dL ConverterBlood lab values between mmol/L and mg/dL by analyte 💉mg to cc ConverterMilligrams to cc using medication concentration 🧪mL to cc ConverterMilliliters and cubic centimeters — identical by definition 💧Drops to mL ConverterDrops to mL and teaspoons using a chosen drop factor 🧪cc to mL Convertercc to mL (identity) plus teaspoons, fluid ounces, and liters 🍎Grams to Calories ConverterGrams of carbs, protein, fat, alcohol to calories (4-4-9-7)🥃cc to Oz Convertercc to US or UK fluid ounces, with mL and teaspoons ⚖️cc to Grams Convertercc to grams via substance density, plus weight ounces 🧴Oz to cc ConverterFluid ounces (US or UK) to cc, mL, and teaspoons 🖐️Body Frame Size CalculatorSmall, medium, or large frame from height ÷ wrist ratio 📦Square Feet to Cubic Yards ConverterArea plus depth to cubic yards for bulk material orders 💱Currency ConverterConvert between major world currencies 🍳Recipe Scaler & ConversionCooking for a different crowd?🔄Unit ConverterConvert between common units 📏Bra SizeSize + sister sizes (US/UK/EU)👟Shoe Size ConversionUS ⇄ UK ⇄ EU ⇄ cm charts 🏛️Roman Numeral ConverterNumbers ⇄ Roman, to 3,999,999 🥄Ounces to CupsFluid ounces to cups and back: 1 cup = 8 fl oz 🔁Pennies to DollarsPennies to dollars, bank rolls & coin weight 🥄Grams to CupsGrams to cups with real baking densities 🥄Cups to PoundsCups to pounds for flour, sugar, butter & more 🥄mL to GramsMilliliters to grams by real density 🥄Quarts to CupsQuarts to cups and back: 1 qt = 4 cups 🥄Pounds to CupsPounds to cups with a tablespoon breakdown 👖Jeans Size CalculatorWaist and hip measurements to US misses, W, or men's W × L jeans size ⚖️Grams to tsp ConverterGrams to teaspoons using ingredient density — water, sugar, salt,🥄tbsp to mL ConverterTablespoons to milliliters — US, metric, Australian 👗Dress Size CalculatorBust-waist-hip measurements to US misses, alpha, EU, and UK dress size 🕐Military Time ConverterMilitary and 12-hour time, both directions, with spoken form 💧mL to tsp ConverterMilliliters to US or metric teaspoons with kitchen fractions 🥛mL to tbsp ConverterMilliliters to tablespoons — US, metric, Australian ♨️Microwave Wattage ConverterAdjust cook times between microwave wattages 🍞Yeast ConverterActive dry, instant, and fresh yeast in tsp, grams, packets 💍Inches to Ring Size ConverterFinger circumference or ring diameter to US and ISO 8653 ring size 🥄tsp to mL ConverterTeaspoons to milliliters, tablespoons, and fluid ounces 💍Cm to Ring Size ConverterFinger measurement in cm to US and EU ring size 📏Ring Size Chart ConverterRing sizes across US, EU, cm, and mm with a full chart 🧄Garlic ConverterConvert garlic between cloves, powder, minced, granulated, and flakes 🧷Belt Size CalculatorBelt size from pant size or waist measurement — US, cm, EU ⚖️tsp to Grams ConverterTeaspoons to grams by ingredient density, plus mL and ounces ⏱️Frames to Timecode ConverterFrame counts to HH:MM:SS:FF timecode, drop-frame included 💊mg to mLmg to milliliters by density or dose strength 🔧Nm to ft-lbsNewton meters to foot pounds instantly 🔁mL to ozMilliliters to US fluid ounces, cups & reverse 🔁Pixels to Inchespx to inches at 72, 96, 150, 300 or custom PPI 🔁oz to mLFluid ounces to milliliters, liters & reverse 📐Circumference to DiameterDiameter = C ÷ π, with radius & area shown 🔁Inches to FractionDecimal inches to nearest 1/8-1/64 fraction 🥄Tablespoons to GramsTablespoons to grams with real ingredient densities 📈Standard Form to Vertex Formax²+bx+c to a(x−h)²+k with the vertex shown 🧪Grams to MolesMass to moles with real molar masses built in 🥄Gallons to PoundsGallons to pounds for water, milk, fuel & more 💊mcg to mgMicrograms to milligrams & back — exact ×1,000 🔁Months to YearsMonths to years and back, mixed & decimal form 📈Cartesian to Polar(x, y) to (r, θ) in degrees or radians 🔁Metric to Inchesmm, cm & meters to inches, feet + 1/16 fraction 🔧Nm to Inch PoundsNewton meters to inch pounds instantly 🔧Inch Pounds to Foot Poundsin-lb to ft-lb (and back) with Nm shown 🥄Quarts to PoundsQuarts to pounds, liquid or dry, by density 💊mcg to mLDose in mcg to mL from label concentration 🔁mL to kgMilliliters to kilograms by liquid density 💊mL to µLMilliliters to microliters & back — exact ×1,000 🔤Letters to Numbers ConverterA1Z26 letters to numbers and back, with totals ⏱️Hours to Days ConverterConvert hours to days (and back), plus 8-hour working days 🥛Grams to Fl Oz ConverterGrams to US fluid ounces via substance density, with mL and cups 📏Km to Miles ConverterKilometers to miles at the exact 1.609344 factor, either direction 📅Days to Weeks ConverterConvert days to weeks (and back) with a weeks-plus-days breakdown 🗓️Days to Months ConverterConvert days to months (and back) using the average 30.44-day month 🔢Million to Billion ConverterMillions to billions on the short scale, with full numerals ⚖️Grams to Ounces ConverterGrams to ounces with the exact 28.3495 factor, plus pounds 🥤Pints to Cups ConverterPints to cups — exact US measure, with UK imperial option 🪣Quarts to Gallons ConverterQuarts to gallons — divide by 4, with pints, cups, and liters 🥄Ounces to Grams ConverterFluid or weight ounces to grams — density-aware conversion ⏳Days to Years ConverterConvert days to years (and back) using the average 365.2425-day year 🛢️Gallons to Quarts ConverterGallons to quarts — times 4, with pints, cups, and liters ⏲️Minutes to Seconds ConverterConvert minutes to seconds (and back) with a min-and-sec breakdown 🗓️Weeks to Months ConverterConvert weeks to months (and back) using the average 4.35-week month 💧Kg to Gallons ConverterKilograms to US gallons via density, with liters 💧PPM to mg/L Converterppm to mg/L with density, the 1:1 identity for water 🏋️Lbs to Kg ConverterPounds to kilograms with the exact 0.45359237 factor 🧪mL to Lbs ConverterMilliliters to pounds via substance density, with grams 🧮Ounces to Pounds ConverterOunces to pounds — divide by 16, with lb-oz and metric 💬Binary to Text ConverterDecode 8-bit binary bytes into ASCII text 🚰Gallons to Kg ConverterUS gallons to kilograms via density, with pounds and liters 🔧Metric to SAE ConverterMetric to SAE wrench sizes with nearest-fit and exact decimals ☕Cups to Pints ConverterCups to pints — divide by 2, with quarts, fl oz, and mL 🧱Cubic Feet to Pounds ConverterCubic feet to pounds by material density, with kg and gallons 🔄Kg to Lbs ConverterKilograms to pounds with the exact 2.20462 factor, plus stone 📐Metric to Standard ConverterMillimeters to standard inch fractions, plus exact decimals 🥛Pints to Pounds ConverterPints to pounds by substance density — pounds, ounces, grams 🌡️Fahrenheit to Celsius ConverterFahrenheit to Celsius with the exact 5/9 formula, plus Kelvin 🧮Number to Million ConverterExpress any number in millions, or expand millions back to full ❄️BTU to Tons ConverterBTU per hour to tons of refrigeration and kilowatts 📶Mbps to Gbps ConverterConvert Mbps and Gbps, with the MB/s rate 📏Feet to Inches ConverterFeet to inches at 12 per foot, with a centimeters readout 🕐Minutes to Hours ConverterConvert minutes to hours (and back) with an hours-and-minutes ➗Decimal to Fraction ConverterDecimals to simplest fractions and mixed numbers, exact or closest 🏃Meters to Miles ConverterMeters to miles at the exact 1,609.344 factor, with kilometers 📅Minutes to Days ConverterConvert minutes to days (and back) with a days-hours-minutes breakdown 💾MB to GB ConverterMB to GB in decimal (1000) and binary (1024)⚖️Kg to Liters ConverterKilograms to liters by substance density — liters, mL, gallons ☕Gallons to Cups ConverterGallons to cups, quarts, pints, and fluid ounces (US, exact)📏Feet to Miles ConverterFeet to miles at 5,280 ft per mile, with yards and meters 🛞kPa to PSI ConverterkPa to psi at 6.894757 kPa per psi, plus bar and atm ⚙️Lbs to Newtons ConverterPounds-force to newtons, kilonewtons, and kilograms-force 🎛️PSIG to PSIA ConverterGauge to absolute pressure: psia = psig + 14.696 🔡Text to Binary ConverterEncode text into 8-bit ASCII binary 📦Cubic Feet to Gallons ConverterCubic feet to US or imperial gallons, plus liters and cubic inches 🍺Pints to Gallons ConverterPints to gallons, quarts, cups, and fluid ounces (US, exact)📡Wavelength to Frequency ConverterFrequency and photon energy from wavelength — vacuum, water, glass,🧪Gallons to Grams ConverterGallons to grams by substance density — grams, kg, pounds 🏋️Pounds to Grams ConverterPounds to grams, kilograms, and ounces — exact 1 lb = 453.59237 g 🧭Complex to Polar ConverterComplex a + bi to r and angle in degrees and radians ⏱️Hours to Weeks ConverterConvert hours to weeks (and back) with a weeks-days-hours breakdown 🚚Gallons to Tons ConverterGallons to short tons, metric tonnes, or long tons by density 💰Billion to Trillion ConverterBillions to trillions on the short scale, 1,000 per step 🧴Fl Oz to Pounds ConverterFluid ounces to pounds by substance density — pounds, ounces, grams 🍺Gallons to Pints ConverterGallons to pints, quarts, cups, and fluid ounces (US, exact)⏳Hours to Years ConverterConvert hours to years (and back) using the average 8,765.82-hour year ➗Fraction to Decimal ConverterFraction to exact decimal, with repeating blocks marked 🌡️Celsius to Fahrenheit ConverterCelsius to Fahrenheit with F = C × 9/5 + 32, plus Kelvin ⚖️Kg to Oz ConverterKilograms to ounces, pounds, and grams — 1 kg = 35.27396 oz 🛢️Cubic Inches to Gallons ConverterCubic inches to US or imperial gallons, plus liters and cubic feet 🗂️KB to MB ConverterKB to MB in decimal (1000) and binary (1024)⏲️Seconds to Hours ConverterConvert seconds to hours (and back) with an h:m:s breakdown 📐Mil to Inches ConverterMils to inches at 0.001 in each, plus mm and microns 🫗Liters to Gallons ConverterLiters to US and imperial gallons, plus quarts and milliliters 💽Byte ConverterConvert B, KB, MB, GB, TB in decimal or binary 💧PPM to Molarity ConverterMolarity from ppm, molar mass and density ⏳Minutes to Years ConverterConvert minutes to years (and back) using the average 📅Weeks to Years ConverterConvert weeks to years (and back) using the average 52.18-week year 🔬nm to M ConverterNanometers to meters at 1e-9 m each, plus microns and Å 🔢Million to Thousand ConverterMillions to thousands, 1,000 per million, with full digits ⏳Seconds to Years ConverterConvert seconds to years (and back) using the average 🔣Hex to Text ConverterDecode hexadecimal bytes into ASCII text ⏱️Hours to Seconds ConverterConvert hours to seconds (and back) with an h:m:s breakdown 🔥CCF to Therms ConverterCCF of natural gas to therms and BTU at about 1.037 per CCF 🛞Lbs to PSI ConverterPounds-force over an area to psi, psf, and kilopascals

Math & Numbers203

🔢PercentageThree percentage questions in one tool 🎓Square Root CurveCurved grade = 10 × √(raw %), with letter & boost 🐠Aquarium Volume CalculatorTank gallons, liters, and water weight from dimensions ✂️Circle Skirt CalculatorWaist and outer cutting radii for full to quarter circle skirts 🍚Rice Water Ratio CalculatorWater needed for rice by type, in cups and milliliters ➗FractionAdd, subtract, multiply, divide with steps 🔬ScientificFull keypad: trig, logs, powers 📉Percent ErrorObserved vs true with steps 🔢ExponentAny base to any power — or solve back 𝑥²Quadratic FormulaRoots, discriminant, vertex, steps √RootSquare, cube & nth roots simplified 🧩LCMLeast common multiple with steps 🧩GCFGreatest common factor two ways 🔎FactorAll factors & prime factorization 🎯RoundingNine rounding modes side by side ✖️Scientific NotationConvert & compute m×10ⁿ 🔟Big NumberExact math on huge numbers ⚖️RatioSolve, simplify & scale A:B = C:D 🪵LogAny base, solve any part, with steps σStandard DeviationSD, variance & margin of error 📊StatisticsFull descriptive summary of a data set ➗Mean Median Mode RangeThe four classic averages 🔢Number SequenceArithmetic, geometric & Fibonacci 🗳️Sample SizeSurvey n from confidence & margin 🎯ProbabilityTwo events or normal distribution 🃏Permutation & CombinationnPr and nCr exactly 📈Z-ScoreZ, percentile & areas under the curve 📏Confidence IntervalCI with z or t, interpreted 📐TriangleSolve any triangle from 3 values 📐Right TriangleTwo values solve everything 📐Pythagorean TheoremFind the missing side 📉SlopeSlope, angle & line equation 🗺️Distance2D, 3D & lat/long distance ⭕CircleRadius ⇄ diameter ⇄ area ⇄ circumference ▭AreaSeven shapes with unit toggle 🧊Surface AreaSeven solids with breakdowns 🧊VolumeSeven solids + tank fill depth 🧪MassMass from density × volume 🪐WeightYour weight on every planet 🏎️SpeedSolve speed, distance or time 🔢MatrixMultiply, invert, determinant to 6×6 💯AverageMean, median, sum & count from any list 📐Arc LengthArc length from radius & angle — degrees or radians 📐Circumference of a CircleC = 2πr = πd from radius, diameter, or area 🧊Volume of a Cylinderπr²h volume with gallons or liters shown 💯Percentage IncreasePercent increase from start to final, with steps 💯RemainderQuotient and remainder from any division 📊P ValueP-value from a z statistic — one- or two-tailed 📐Diameter of a Circled = 2r, C ÷ π, or 2√(A ÷ π) — with steps 🧪Net Ionic EquationMolecular, complete & net ionic for 13 reactions 📐Area of a CircleA = πr² from radius, diameter, or circumference 📐HypotenuseHypotenuse from two legs, or a missing leg 💯Percent ChangePercent change between old and new, with direction 📐Area of a SectorSector area from radius & angle, plus arc length 📐TrigonometrySolve right triangles: sides, angles, sin cos tan 📈Exponential GrowthProject growth with x₀(1+r)^t plus doubling time 📐45 45 90 TriangleAll sides of a 45-45-90 from any one side 📐Trapezoid AreaTrapezoid area from bases and height 📊Critical ValueCritical z for 90–99% confidence, one/two-tailed 🧊Cone Volume⅓πr²h cone volume with gallons or liters 🧪Percent YieldActual ÷ theoretical × 100, with worked steps 📐PerimeterPerimeter of rectangles, squares, triangles, circles 💯Log Base 2Base-2 logarithm with exact powers flagged 📐Area of a SemicircleHalf-circle area & perimeter from radius or diameter 📐Radius of a Circler from circumference, diameter, or area — with steps 💯Average PercentageMean of percentages, weighted or simple ⚡Specific HeatQ = mcΔT — solve heat, specific heat, mass, or ΔT 🧊Volume of a Triangular Prism½ × b × h × L with gallons or liters shown ⚡Wet Bulb TemperatureWet-bulb temp from temperature & humidity (Stull)⚡Torqueτ = F × r × sin θ in N·m, ft-lb & in-lb 💯Cross MultiplicationSolve proportions: find the missing value 📐Area of TriangleTriangle area from base-height or three sides 🧊Volume of Triangular Pyramid⅓ × base area × height, any unit 💯Round to the Nearest CentRound dollars to the nearest cent, with steps 💯Round to the Nearest TenthRound to tenths, hundredths & more, with steps 💯Sig FigCount & round significant figures instantly 💯Percent DecreasePercent drop from start to final, with steps ⛰️Slope Percentage CalculatorRise/run to percent grade, degrees, and 1-in-N ratio ⚖️Percentage Difference CalculatorSymmetric percent gap between two values — |a−b| over their mean 🎡Roulette Payout CalculatorRoulette bet payouts, win odds, and house edge ✖️Multiplication CalculatorExact product of any two numbers, with an estimate check ⬡Hexagon CalculatorSolve a regular hexagon from side, diagonal, perimeter, or area 🖼Diagonal of a Rectangle CalculatorCorner-to-corner diagonal from length and width — d = √(l² + w²)📊T Statistic CalculatorOne-sample t statistic with df and critical-value verdict 🪙Coin Flip Probability CalculatorExact binomial odds for heads in n coin flips 💠Diamond Problem CalculatorTwo numbers from their product and sum — the factoring X puzzle ⭕Cross Sectional Area CalculatorArea of round, pipe, and rectangular sections — πd²/4 and friends 🔺Equilateral Triangle CalculatorSide, height, area, and radii of an equilateral triangle from any ✂️Simplify Fractions CalculatorAny fraction to lowest terms — exact GCD, mixed number, decimal 📦Pounds and Ounces CalculatorPounds and ounces to decimal lb, total oz, and metric 📏Distance Formula CalculatorDistance between two points — exact radical plus midpoint ⚖️Greater Than Less Than CalculatorCompare two values and get the right inequality symbol 🎯Implied Probability CalculatorConvert betting odds to probability and strip the vig 📍Point Estimate CalculatorBest estimate of a proportion from successes and trials 📍Point Slope Form Calculatory − y₁ = m(x − x₁) from a point and slope, with conversions 📦Volume of a Rectangular Prism CalculatorBox volume from l × w × h with gallons, liters, and surface area 🚰Volume of a Trapezoidal Prism CalculatorDitch, trough, and ramp volume from a trapezoid cross-section × length ➗Long Division CalculatorQuotient, remainder, decimal, and mixed number in one shot 🛑Octagon CalculatorRegular octagon area, span, and sides from any one measurement ➕Sum of Series CalculatorArithmetic, geometric, and infinite geometric sums with formulas 🥣Volume of a Hemisphere CalculatorHalf-sphere volume from radius or diameter, with gallons and liters ⛈️Lightning Distance CalculatorStorm distance from the flash-to-thunder delay 📉Average Rate of Change CalculatorSecant slope (f(b) − f(a))/(b − a) between two points ⛺Surface Area of a Triangular Prism CalculatorAll five faces of a triangular prism from three sides and a length 🌻Golden Ratio CalculatorSplit any length into golden-ratio segments with φ = 1.618 📉Friction Loss CalculatorHazen-Williams friction head loss for water in pipe 🔢Least to Greatest CalculatorSort any list ascending and descending, fractions included 📐30 60 90 Triangle CalculatorSolve a 30-60-90 triangle from any one side with the 1 : √3 : 2 ratio ⬜Diagonal of a Square CalculatorSide to diagonal and back with d = a√2, plus area and perimeter ➡️Vector CalculatorMagnitude, unit vector and direction from x, y, z 🥧Pie Chart CalculatorValues to pie chart percentages and degrees per slice ⚗️Molality CalculatorMolality in mol/kg from solute and solvent mass 🌍Earth Curvature CalculatorCurvature drop, horizon distance, and hidden height 🔄Standard Form to Slope Intercept CalculatorAx + By = C to y = mx + b, with fractions kept exact 🎲Binomial Coefficient CalculatorC(n, k) and P(n, k) — combinations and permutations, exactly 📈Constant of Proportionality CalculatorFind k for direct (y = kx) or inverse (y = k/x) variation ⛰️Potential Energy CalculatorGravitational PE = mgh in joules and foot-pounds 📈Slope Intercept Form Calculatory = mx + b from slope, point, or two points — with intercepts 🍎Free Fall CalculatorFall time and impact speed from a height or a time ⚡Joules to Volts CalculatorVolts from energy and charge, V = joules per coulomb 🔷Regular Polygon CalculatorArea, apothem, radius, and angles for any regular n-sided polygon 📐Line Equation from Two Points CalculatorSlope, intercept, and three equation forms from two points ⏱️Time Dilation CalculatorLorentz factor and dilated time from speed 🎯Linear Interpolation CalculatorEstimate y between two known points — lerp with a warning light 🌊Wave Speed CalculatorSolve v = fλ for speed, frequency, or wavelength 🔁Antilog CalculatorInverse logarithm b^x for base 10, e, 2, or any custom base 🔔Empirical Rule Calculator68-95-99.7 ranges from a mean and standard deviation 🌿Simpson's Diversity Index CalculatorSimpson's D, 1-D, and reciprocal from species counts 🧲Coulomb's Law CalculatorElectrostatic force between two point charges 📏Vector Magnitude CalculatorLength of a 2D or 3D vector from its components 🧪PPM CalculatorParts per million from a part and whole, plus percent and fraction 📏Line Segment Length CalculatorDistance, midpoint, and slope between two coordinate points 🌗Surface Area of a Hemisphere CalculatorCurved, base, and total surface area of a half-sphere ⊥Gram Schmidt CalculatorOrthonormalize 2 or 3 vectors, with steps ⚖️Center of Mass CalculatorBalance point of up to 3 point masses in 2-D — mass-weighted average 🌀Moment of Inertia CalculatorRotational inertia I for spheres, disks, hoops, rods, and point masses 🎯Expected Value CalculatorE(X), variance, and SD from outcomes and probabilities 🔢Round to the Nearest Integer CalculatorNearest whole number with the .5 tie rule, floor, and ceiling 📶Dipole CalculatorHalf-wave dipole length in feet and meters from MHz 💨Partial Pressure CalculatorPartial pressure from mole fraction and total pressure ⬠Pentagon CalculatorRegular pentagon area, diagonal, apothem, and height from any one 📐Angle Between Two Vectors CalculatorAngle between two vectors in degrees and radians 📐Section Modulus CalculatorSection modulus S = I/c for beam cross-sections ⛰Surface Area of a Square Pyramid CalculatorBase, faces, and total area of a square pyramid from base and height 🎯Vector Projection CalculatorProjection of a onto b, scalar and rejection 💨Wind Load CalculatorScreening wind pressure and force from wind speed ⭐5-Star Rating CalculatorWeighted star average and ratings needed for a target 🔁Powers of i CalculatorSimplify i^n through its four-step cycle 📐Surface Area of a Trapezoidal Prism CalculatorTotal and lateral surface area from bases, height, legs, length ⚙️Efficiency CalculatorEfficiency as output over input, with loss 📏Relative Error CalculatorRelative, percent, and absolute error vs a true value 🧪T Test CalculatorOne-sample, paired, or Welch two-sample t test 🌱Shannon Diversity Index CalculatorShannon H, Pielou evenness, and effective species 🧮Round to the Nearest Thousand CalculatorRound any number to the nearest 1,000 with the deciding digit 💯Round to the Nearest Hundred CalculatorRound any number to the nearest 100 with the deciding digit explained ⭕Circumcenter CalculatorCircumcenter, circumradius, and circle equation from 3 vertices 📦Rectangular Prism CalculatorVolume, surface area, and diagonal of a box 📊Class Width CalculatorClass width from a data set or min, max, and classes ➕Vector Addition CalculatorResultant, magnitude and direction of a + b 🧭Coterminal Angles CalculatorReduce any angle to [0°, 360°) and list its coterminal family ⚖️Specific Gravity CalculatorConvert between specific gravity and density 🎁Surface Area of a Rectangular Prism CalculatorSA = 2(lw + lh + wh) with face breakdown 📈Least Squares Regression CalculatorBest-fit line, slope, intercept, r, and r squared 🌊Evaporation Rate CalculatorPool and open-surface water evaporation estimate 📍Orthocenter CalculatorOrthocenter from three vertices, plus Euler line points 🟦Perfect Square CalculatorIs n = k²? Square-root test with the nearest squares either side ✂️Round to the Nearest Hundredth CalculatorRound decimals to two places with the thousandths digit rule shown 🪜Arithmetic Sequence Calculatornth term and partial sum from a₁, d, and n — formulas shown ⚛️Average Atomic Mass CalculatorWeighted average atomic mass from isotope abundances ⛰️Volume of a Square Pyramid CalculatorV = a²h/3 from base edge and height or slant 🔬Electron Configuration CalculatorFull and noble-gas electron configuration from Z 📐Arctan Calculator (tan⁻¹)Inverse tangent in degrees, radians, and π multiples 🔦Snell's Law CalculatorRefraction angle, critical angle, and in-medium light speed 🔺Isosceles Triangle CalculatorSolve area, sides, and angles from any two knowns 🧪Mass Percent CalculatorPercent by mass, solution mass and ppm from two masses 🏹Arrow Speed CalculatorReal-world fps from IBO rating and your setup, with hunting KE bands 🎯Endpoint CalculatorMissing endpoint from start point and midpoint 🪐Kepler's Third Law CalculatorOrbital period from distance (or back) around Sun, Earth, Mars,📏Isosceles Trapezoid CalculatorArea, height, leg, diagonal, and angles 💥Impulse CalculatorImpulse from F×Δt or m×Δv — N·s and lbf·s 〰️LC Filter CalculatorLC filter cutoff frequency and characteristic impedance 📈e^x CalculatorNatural exponential e^x with reciprocal and growth interpretation 🎯Pressure CalculatorPressure P = F/A in Pa, psi, bar, and atm 🌙Circle Segment Area CalculatorSegment area from radius plus angle or height ⚡Power Factor CalculatorPower factor, phase angle and kVAR from kW and kVA 🧻Volume of a Hollow Cylinder CalculatorWall volume of tubes and pipes: π(R² − r²)h 🩺Sensitivity and Specificity CalculatorSensitivity, specificity, PPV, NPV from a 2x2 table 🌊Hydrostatic Pressure CalculatorWater pressure at depth, P = rho g h, gauge or absolute ⚛️Atom CalculatorProtons, neutrons and electrons from element and mass ➗Divisibility CalculatorWhich of 2-12 divide your number, with the digit rules shown 🧊Surface Area to Volume Ratio CalculatorSA, volume, and SA:V for spheres, cubes, and cylinders ➖Subtraction Calculatora − b with the addition check and number-line reading 🥚Ellipse Circumference CalculatorOval perimeter by Ramanujan, plus area and eccentricity 🌊Phase Shift CalculatorPhase shift, amplitude, period, and midline from A, B, C, D 🎲Probability of 3 Events CalculatorAll, none, at least one, exactly one for 3 events 🎯Muzzle Energy Calculator (FPE)Foot-pounds of energy from grains and fps, plus joules and power 🏛️Volume of a Rectangular Pyramid CalculatorV = lwh/3 with base area and slant heights ✂️Midpoint CalculatorMidpoint, length, slope, and quarter points 🔔Central Limit Theorem CalculatorSampling mean, standard error, and normal probabilities 💧Water Viscosity CalculatorWater's dynamic and kinematic viscosity plus density at any 🌐Spherical Coordinates CalculatorConvert x, y, z to spherical r, theta, phi and back 🔍Similar Triangles CalculatorScale factor and missing sides of similar triangles ✖️Cross Product Calculatora x b, its magnitude and the spanned area

Science & Engineering42

🥶Wind ChillNWS feels-like cold + frostbite times 🥵Heat IndexNWS feels-like heat & danger levels 💧Dew PointDew point & comfort from temp + RH ⚡Ohm's LawAny two of V, I, R, P solve the rest ⚡Voltage DropWire-run drop vs the NEC 3% guide 🎨Resistor Color CodeDecode bands or find them 🧪DilutionSolve C1V1 = C2V2 and the water to add ❄️Rain to Snow CalculatorLiquid precipitation to snowfall by temperature band ☢️Half-LifeSolve decay: N0, Nt, t or t½ 🧪DensitySolve density, mass or volume ⚗️MolarityConcentration & dilution (M1V1=M2V2)⚗️Molecular WeightMolar mass from any formula ⚡VelocitySolve v = d ÷ t for velocity, distance, or time ⚡Accelerationa = (v − u) ÷ t, with g-force and F = ma 🧪MoleMoles from mass or particles, plus grams back ⚡WattageWatts = volts × amps, plus amps, volts & daily kWh ⚡Angular Velocityω = θ ÷ t, RPM ↔ rad/s & tangential speed 🧪pHpH from molarity, plus pOH and ion concentrations 💧Relative Humidity CalculatorRelative humidity from temperature and dew point 🌀Reynolds Number CalculatorReynolds number and laminar vs turbulent flow ⚡HP to Amps CalculatorFull-load amps from horsepower, volts and phase 🪂Terminal Velocity CalculatorTerminal speed from mass, area, drag, and air density 🚿Flow Rate CalculatorVolumetric flow Q = A×v in L/min, GPM, m³/h, CFM 📡Resonant Frequency CalculatorLC resonant frequency, angular frequency and period 🧪Ideal Gas Law CalculatorSolve PV = nRT for P, V, n, or T in any units 📋Relative Frequency CalculatorCounts to relative and cumulative frequencies 〰️Frequency CalculatorFrequency in hertz from period, wave, or angular input 🪐Gravitational Force CalculatorNewton's F = Gm1m2/r squared in newtons and lbf ⚡Kinetic Energy CalculatorEnergy of motion from mass and speed — joules and ft-lb 🔧Pipe Flow CalculatorWater velocity in a pipe from diameter and flow 🎢Grams Force CalculatorAcceleration in g from speed change and time, plus the force on a body 🌫️Absolute Humidity CalculatorActual water vapor in air, g/m³ and grains/ft³ 🌊Wavelength Calculatorλ = v/f for light, sound, or any wave — km down to nm 🎈Air Density CalculatorAir density from pressure, temperature, humidity 🧫Serial Dilution CalculatorSerial dilution series, per-step and total dilution 🔌Capacitive Reactance CalculatorCapacitive reactance Xc in ohms from f and C 🕳️Schwarzschild Radius CalculatorEvent-horizon radius from mass — solar masses, Earth masses, or kg 🔨Impact Force CalculatorAverage impact force from energy and stopping distance 🛟Buoyancy CalculatorBuoyant force from Archimedes' principle, float check 🧭Net Force CalculatorResultant magnitude and direction of two angled forces — N, lbf, kN 🛠️Cylinder Force CalculatorPneumatic and hydraulic cylinder push and pull force 🔥Enthalpy CalculatorΔH from ΔU + pΔV or from m·c·ΔT — kJ, kcal, BTU

Time & Date57

⏰OvertimeWork out your overtime and total weekly pay — and confirm your overtime multiplier meets…💰Average Net Worth by AgeFed SCF medians by age — see where you stand 📈Average 401(k) by AgeFidelity Q1 2026 averages by generation 🏦Average Savings by AgeMedian bank balances by age (Fed data)💳Average Credit Score by AgeExperian FICO averages by generation 💎Net Worth by AgeHow does your net worth stack up?🤰Pregnancy Due DateEstimate your due date from the first day of your last period — plus how far along you…👶Adjusted Age CalculatorCorrected age for premature babies, in weeks and months 🏭Takt Time & Cycle TimePace a line to demand 📅AgeFind an exact age between two dates 📅Date DifferenceCount the time between two dates 📖Reading TimeEstimate reading time from a word count and reading speed ⏱️HoursHours between times, minus breaks ⏳Time DurationExact time between two moments 🌍Time ZoneConvert times across 34 zones 📆Day CounterDays or business days between dates 📅Day of the WeekWhat day any date falls on ⏰TimeAdd or subtract times & durations 🕒Birth YearBirth year from your age — both birthday cases 🕒Time UntilHours & minutes until any time, across midnight 🕒Hours UntilHours left until any hour — even past midnight 🕒CountdownDays, hours, minutes & seconds until any moment 🧮Download TimeHow long a file takes at your speed 🕒Days Until DecemberDay count to any December date, with weekday 🕒30 Minutes From NowExact time 30 (or any) minutes from now 🕒6 Months From TodayDate 6 months ahead or back — weekday included 🎂Birthday CalculatorNext birthday date, weekday, countdown, and age you turn 📆Years Between Dates CalculatorExact years, months, and days between any two dates 📅90 Days From TodayExact date 90 days ahead, with weekday and business-day variant 🗓️Month CounterMonths between two dates — full, decimal, and touched 📅180 Days From TodayExact date 180 days ahead, weekday, and business-day variant 📅30 Days From TodayExact date 30 days ahead, weekday, and business-day variant 👥Age Difference CalculatorExact age gap between two birth dates, plus ages today ⏪How Old Was I? CalculatorYour exact age on any past or future date 📍Day of Year CalculatorDay number 1-365, days left, week number, year progress 📅45 Days From TodayExact date 45 days ahead, weekday, and business-day variant 🌞Days Until JuneDays until June 1, plus days left in June 🎓Graduation Year CalculatorHigh school and college class year from birth date or grade 📅60 Days From TodayExact date 60 days ahead, weekday, and business-day variant 💯100 Days From TodayExact date 100 days ahead, weekday, and business-day variant 💼Business Days CalculatorWeekday count between two dates, minus weekends 💍Anniversary CalculatorYears, months, and days together plus your next anniversary date 📅120 Days From TodayExact date 120 days ahead or back, calendar or business days 🎂Birthday Countdown CalculatorDays until your next birthday and the age you'll turn 🌙Lunar Age CalculatorTraditional East Asian age from Lunar New Year, plus zodiac 🔋Battery Charge Time CalculatorCharge time from capacity, charger amps, and chemistry efficiency 📆Age in Days CalculatorExact days alive, with weeks and 1,000-day milestones 🥫Expiration Date CalculatorUse-by date from production date and shelf life 🇰🇷Korean Age CalculatorKorean traditional, year-counting, and official international age 💘Days Until Valentine's DayExact days, weeks, and weekdays until February 14 👶Age in Months CalculatorExact age in calendar months and days - baby-milestone ready 🎄Days Until ChristmasDays, weeks, and Saturdays left until December 25 🍂Days Until FallCountdown to the equinox or September 1 - your pick 🐸Leap Year CalculatorLeap-year check with the full Gregorian century rule 🧫Cell Doubling Time CalculatorDoubling time, doublings, and growth rate from two counts and time ⏱️Age in Seconds CalculatorSeconds alive from birth date and time, with gigasecond milestones 🏃Mile TimeGood mile by age + splits & pace

Text & Data Tools9

🔐Password GeneratorCrypto-random with entropy & crack time 🔤Base64 Encode / DecodeUTF-8-safe, runs locally 🔗URL Encode / DecodePercent-encoding both directions 🎲Dice Rollerd4–d20 + custom, with history 🟩Minecraft Circle GeneratorOutline and filled block counts for a Minecraft circle of any diameter 🎲Random Number GeneratorCrypto-secure randoms in any range 💻BinaryBinary math, conversion & bitwise 🔡HexHex arithmetic & conversion 🎲Dice Average CalculatorAverage, range, and swing of any NdS dice roll

Education & Test Scores13

🎓Final GradeWhat do you need on the final?🎓GPACalculate your GPA on a 4.0 scale 🎓Weighted GradeEnter each category’s weight and your score to get your current weighted grade…🎓GradeTest % + letter grade from points or wrong answers 🎓Semester Grade CalculatorTwo quarters plus the final exam, weighted into a semester grade ⌨️Keystrokes per Hour CalculatorWPM to KPH conversion and timed-test scoring for data entry ⏱️Words per Minute CalculatorGross WPM, net WPM, and accuracy from any typing test 🎒What Grade Was I In? CalculatorGrade for any year from your birth date 🧮Average Typing Speed: 40–52 WPM — Benchmarks by Level — NumberBenchThe average typing speed is about 40–52 WPM depending on population. Benchmarks from a 136-million-keystroke study, plus professional standards.🧮What Is a Good ACT Score? Percentiles for Every Composite — NumberBenchThe average ACT composite is 19.4. Full percentile table for scores 9–36 and what counts as good for selective admissions.🧮What Is a Good GPA? High School & College Averages — NumberBenchThe average U.S. high school GPA is about 3.11; the average college GPA is about 3.15. What counts as good — with real admissions numbers.🧮What Is a Good PSAT Score? Percentiles + National Merit Cutoffs — NumberBenchThe average PSAT/NMSQT score is about 950. See junior-year percentiles for every score band and the National Merit Selection Index cutoffs.🧮What Is a Good SAT Score? 2025–26 Percentiles by Score — NumberBenchA good SAT score is above the 1029 average. See the official percentile for every score, what counts as good for selective schools, and where your score lands.

Everyday Life45

🌍Carbon FootprintEstimate your annual carbon footprint from driving, flights, home energy and diet —…😊Happiest Cities in AmericaHappiness is personal, so this tool lets you set the rules 😊HappinessDecades of well-being research keep landing on the same handful of levers 🧭How long does it take to get anywhere?Pick any starting city and see the door-to-door travel time to every country on Earth…🎰Lottery Expected ValueIs a lottery ticket ever “worth it”?⛳Golf HandicapUSGA Handicap Index from your scores 🔁Unit Conversion12 categories, exact factors shown 🌐IP SubnetIPv4/IPv6 network, range & mask 📶BandwidthTransfer time, usage & site bandwidth 💘LoveName compatibility — just for fun 🧮Desk HeightErgonomic desk height for your body 🧮AudiobookReal listening time at any playback speed 🧮eDPITrue mouse sensitivity: DPI × in-game sens 🧠IQ Percentile CalculatorPercentile, z-score, and 1-in-N rarity from an IQ score 🔠Gematria CalculatorSimple, English, and Hebrew gematria values for any word or phrase 🚩Flag Size CalculatorRight flag size for any pole via the 1/4-1/3 fly rule 🍚Rice Conversion CalculatorDry to cooked rice, water ratio, and servings by rice type 🚲Bike Size CalculatorRoad, mountain, or hybrid frame size from height and inseam 🎯KD Ratio CalculatorK/D ratio and KDA from kills, deaths, and assists with a rating band 🌮Taco Bar CalculatorMeat, tortillas, and toppings for a taco bar crowd 📺TV Mounting Height CalculatorScreen-center mounting height from eye level, recline, and SMPTE 👶Baby Age CalculatorBaby's age in weeks, months, and days from the birth date 📦Dimensional Weight CalculatorDIM weight and billable weight from box size for FedEx, UPS, USPS, DHL 🐉Point Buy CalculatorD&D 5e point buy: points spent, points left, and budget check 🍕Pizza Party CalculatorPizzas to order via the 3/8 rule — slices per guest math 🌀Nether Portal CalculatorConvert coordinates between the Overworld and Nether at the 1:8 scale 🧳Linear Inches CalculatorL + W + H against the 62 in checked and 45 in carry-on limits 🎤Vocal Range CalculatorOctaves, semitones, Hz, and voice type from your lowest and highest 📦Minecraft Stack CalculatorItems into stacks, shulker boxes, and double chests with the remainder 🍕Pizza Size CalculatorCompare pizza sizes by area and cost per square inch ❤️D&D HP CalculatorAverage, max, and min D&D 5e hit points by hit die, level, and CON 🖥️Screen Size CalculatorTrue width, height, and area from any diagonal and aspect ratio 📷Field of View CalculatorLens angle of view from focal length and sensor size 🖥️Resolution Scale CalculatorScale a resolution by percent — new dimensions and megapixels 🧵Fabric CalculatorYards of fabric to buy from piece size, count, and bolt width ⛵Boat Speed CalculatorDisplacement hull speed in knots, mph, and km/h from waterline length 🏛️BC to AD CalculatorYears between BC and AD dates - no-year-zero rule applied 🪟Curtain Size CalculatorCurtain panel width and length from window size and fullness 🚲Chain Length CalculatorBicycle chain length in inches and links from chainstay and gearing 🎈Helium Balloon CalculatorHow many helium balloons to lift a weight, plus tank math 🔍Pixels per Inch CalculatorPPI, dot pitch, and megapixels from resolution and screen size 🎬Video File Size CalculatorVideo size in MB/GB from bitrate and runtime 🐠Aquarium Glass Thickness CalculatorEstimate minimum aquarium glass thickness from height and safety 👔Jacket Size CalculatorUS suit/jacket size with length letter from chest and height 📄Paper Weight CalculatorWeight of a paper stack from stock, size, and sheet count

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