Cubic Feet Calculator
Multiply length × width × height and convert to cubic feet in one step — enter your measurements in inches, feet, centimeters, or meters and the unit math is handled for you.
Example: with Length 24 · Width 18 · Height 16 · Measured in inches (in) → Volume: 4.00 ft³.
Computed by the calculator below using its default values. Change any input to see your own numbers.
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Check it outHow to calculate cubic feet from inches
Cubic feet = length × width × height, with every side in feet. If you measured in inches, multiply the three numbers, then divide by 1,728 (12³) — not by 12. The default box above is 24 × 18 × 16 in = 6,912 in³, and 6,912 ÷ 1,728 = 4.00 cubic feet — a typical large moving box.
In feet the product is already cubic footage: a 10 × 10 ft room with an 8 ft ceiling holds 800 ft³. Divide cubic feet by 27 for cubic yards (that room is 29.63 yd³) when ordering mulch, soil, or concrete, and multiply by 0.0283168 for cubic meters when a freight or shipping form asks for m³. Appliance capacities work the same way: a fridge interior of roughly 28 × 30 × 60 in is 50,400 in³ ≈ 29.2 cu ft.
How it’s calculated
Volume = length × width × height, converted to cubic feet: inches ÷ 1,728 (12³ exactly), centimeters ÷ 28,316.846592 (30.48³ exactly), meters × 35.3146667. Cubic yards = ft³ ÷ 27 exactly; cubic meters = ft³ × 0.028316846592 (exact, since 1 ft = 0.3048 m).
Results update as you type and are estimates, not professional advice — verify important decisions with a qualified professional.
Common mistakes
- Dividing inch measurements by 12 instead of 1,728 — the cube of the conversion applies, so the result comes out 144× too big.
- Mixing units, like inches for depth and feet for length — convert every side to the same unit first.
- Confusing square feet (floor area) with cubic feet (volume) — storage, freight, and appliances are priced on volume.
Frequently asked questions
How do I calculate cubic feet from inches?
Multiply length × width × height in inches, then divide by 1,728. A 24 × 18 × 16 in box is 6,912 in³ ÷ 1,728 = 4.00 cu ft.
How many cubic feet are in a cubic yard?
Exactly 27 (3³). Divide cubic feet by 27 to get cubic yards — 800 ft³ of soil is 29.63 yd³.
How many gallons are in a cubic foot?
About 7.48 US gallons — exactly 1,728 ÷ 231, since a gallon is defined as 231 cubic inches.
Is cubic feet the same as square feet?
No. Square feet measure a flat area (length × width); cubic feet add the third dimension (× height) and measure volume. A 100 sq ft room with an 8 ft ceiling contains 800 cu ft.