Pressure calculator
In the pressure calculator, 150 pounds-force on a heel 0.25 square inches in area is 600 psi, or 4.137 MPa, since P = 150 ÷ 0.25.
Pressure P
- Pressure P P = F / A = 667.2 N / 0.0001613 m² = 4,137,000 N/m² = 4,137,000 Pa.
- 600 psi (4,137,000 Pa)
- The unit algebra A pascal is one newton on one square meter. A psi is one pound-force on one square inch, 6,894.76 Pa.
- N / m² = Pa
- Pressure in other units
- 4,137,000 Pa 4,137 kPa 4.137 MPa 41.37 bar 600 psi 40.83 atm
- Force
- 667.2 N 0.6672 kN 150 lbf
- Area
- 0.0001613 m² 1.613 cm² 161.3 mm² 0.25 in² 0.001736 ft²
| Area | Pressure | In psi |
|---|---|---|
| 0.0625 in² | 2,400 psi (16,550,000 Pa) | 2,400 psi |
| 0.125 in² | 1,200 psi (8,274,000 Pa) | 1,200 psi |
| 0.25 in² | 600 psi (4,137,000 Pa) | 600 psi |
| 0.5 in² | 300 psi (2,068,000 Pa) | 300 psi |
| 1 in² | 150 psi (1,034,000 Pa) | 150 psi |
| 2.5 in² | 60 psi (413,700 Pa) | 60 psi |
- This is the average pressure over the area. A tire gauge or a tank gauge reads gauge pressure, the amount above the surrounding air; absolute pressure adds one atmosphere, 101,325 Pa (14.70 psi).
- Results are shown to four significant figures. Round to the precision of your least precise measurement.
How the Force Calculator works
Pressure is force divided by the area it acts on: P = F / A. One newton on one square meter is a pascal (Pa), and one pound-force on one square inch is a psi. The same force on a smaller area makes a higher pressure, which is how a knife edge, a nail point and a snowshoe all work.
Worked example: a 150 lb person standing on one heel with 0.25 in² touching the floor presses down with 150 lbf, so P = 150 ÷ 0.25 = 600 psi. In SI units the force is 667.2 N and the area 0.0001613 m², which gives 4,137,000 Pa, or 4.137 MPa.
Rearranged, the formula gives the other two. Force is pressure times area, F = PA: air at 32 psi acting on 20 in² pushes with 640 lbf. Area is force over pressure, A = F / P: to carry a 50 kN load at no more than 2 MPa, a bearing surface needs 50,000 ÷ 2,000,000 = 0.025 m², or 250 cm².
The units follow from the definitions: 1 psi = 6,894.757 Pa, 1 bar = 100,000 Pa = 14.50 psi, and 1 standard atmosphere = 101,325 Pa = 14.70 psi. Divide in matching units: pounds-force over square inches gives psi, newtons over square meters give pascals, and newtons over square centimeters give N/cm², which is 10,000 Pa.
A tire gauge or a tank gauge reads gauge pressure, the amount above the surrounding air. Absolute pressure adds the atmosphere, so a tire at 32 psi gauge is at about 46.7 psi absolute at sea level.
Force Calculator FAQ
How do I convert psi to pascals?
Multiply by 6,894.757. 32 psi is 220,600 Pa, which is 220.6 kPa or 2.206 bar.
Why does a smaller area give a higher pressure?
The same force is shared by fewer square inches, so each one carries more. Halve the area under 150 lbf from 0.25 in² to 0.125 in² and the pressure doubles, from 600 psi to 1,200 psi.
What is the difference between pressure and force?
Force is the total push, in newtons or pounds-force. Pressure is that push per unit of area. A 150 lb person exerts the same 150 lbf through a heel or a flat shoe, but 600 psi through a 0.25 in² heel and 5 psi through a 30 in² sole.
More from the Force Calculator
Sources
- NASA NSSDCA Moon Fact Sheet, bulk parameters table, row "Surface gravity (m/s2)", Moon column (page last updated January 11, 2024) (2026)
- NASA NSSDCA Mars Fact Sheet, bulk parameters table, row "Surface gravity (mean) (m/s2)", Mars column (page last updated May 19, 2025) (2026)