Pressure Calculator
Compute pressure as force divided by area, P = F/A. Enter the force in newtons, pounds-force, or kilograms-force and the area in m², cm², mm², in², or ft² — the tool returns pressure in pascals, kPa, psi, bar, and atmospheres.
Example: with Force 500 · Force unit newtons (N) · Area 25 · Area unit cm² → Pressure: 200,000 Pa (200.00 kPa).
- In psi29.008 psi
- In bar and atm2.0000 bar (1.9738 atm)
Computed by the calculator below using its default values. Change any input to see your own numbers.
Pressure is how concentrated a force is: the same push over a smaller area presses harder. That is why a sharp knife cuts and snowshoes keep you on top of the snow.
Force, spread over area
Pressure is force divided by the area it acts on, P = F/A, measured in pascals (one newton per square meter) in SI. The force alone does not tell you how hard something presses — the area does the rest. A 150-pound person on flat feet spreads their weight over broad soles and barely dents the ground; the same person in stiletto heels concentrates it onto a tiny area and can punch through a wood floor.
That inverse relationship with area explains a lot of everyday physics. Sharp blades, needles, and nails work by shrinking the contact area until the pressure is enough to cut or pierce, while snowshoes, wide tires, and foundation footings do the opposite, enlarging the area to keep pressure low. This calculator moves freely between the units engineers actually use — pascals, psi, bar, and atmospheres — so you can match whatever a spec sheet quotes.
How it’s calculated
P = F/A. Force converts to newtons (lbf ×4.4482216, kgf ×9.80665); area to m² (cm² ÷1e4, mm² ÷1e6, in² ×0.00064516, ft² ×0.09290304). Pressure in pascals then scales: kPa ÷1000, psi ÷6894.757, bar ÷100000, atm ÷101325.
Gives uniform average pressure over the stated area, F perpendicular to the surface. Real contact pressure can peak much higher where the load concentrates.
Pressure unit equivalents
| Pressure | In psi | In kPa |
|---|---|---|
| 1 Pa | 0.000145 | 0.001 |
| 1 kPa | 0.145 | 1 |
| 1 psi | 1 | 6.895 |
| 1 bar | 14.50 | 100 |
| 1 atm | 14.70 | 101.3 |
Standard unit conversions (NIST); rounded.
Common mistakes
- Mixing force and pressure — pounds-force is a force, psi (pounds per square inch) is a pressure.
- Leaving area in cm² or mm² without converting to m² before dividing newtons.
- Confusing gauge pressure with absolute; this tool computes the pressure from your force and area directly.
- Assuming the average pressure is uniform when a real contact patch concentrates load at its edges.
Frequently asked questions
What is the pressure formula?
P = F/A, force divided by area. In SI, a force in newtons over an area in square meters gives pressure in pascals (1 Pa = 1 N/m²).
How do I convert pascals to psi?
Divide pascals by 6894.757. So 200,000 Pa is about 29 psi. This tool also shows kPa, bar, and atmospheres.
Why does a smaller area mean higher pressure?
The same force is concentrated onto less surface, so each unit of area carries more of it. That is why a sharp point pierces while a blunt one does not.
What is the difference between bar and atm?
They are close but not equal: 1 bar is exactly 100,000 Pa, while 1 standard atmosphere is 101,325 Pa. A bar is about 0.987 atm.