Pounds Per Square Inch (PSI) Calculator — Force & Area to Pressure
Enter a force in pound-force and the area it acts over in square inches to calculate the resulting pressure in PSI — with instant conversion to pascals, kPa, MPa, bar, atmospheres and mmHg.
lbf
in²
PSI = Force (lbf) ÷ Area (in²) • 1 psi = 6,894.757 Pa
- 1
Force and area
F = 100 lbf, A = 2 in² - 2
Pressure = Force ÷ Area
100 ÷ 2 = 50PSI = pound-force per square inch; pressure is force distributed over area.
How does this calculator work?
PSI = Force (lbf) ÷ Area (in²). 1 psi = 6,894.757 Pa = 6.895 kPa = 0.06895 bar = 0.06805 atm = 51.715 mmHg. Enter the force and area to get PSI and all common pressure equivalents. Add 14.696 psi to convert from gauge (psig) to absolute (psia) pressure.
Formula
How this is calculated
Pressure is defined as force divided by the area over which that force acts: P = F / A. When force is measured in pound-force (lbf) and area in square inches (in²), the result is pounds per square inch — PSI. One pound-force is the force exerted by one avoirdupois pound under standard gravity (9.80665 m/s²), giving the exact conversion 1 psi = 6,894.757 293 168 Pa from the precise definitions of the pound and the inch.
This calculator takes your force and area inputs, computes the PSI, and then converts to SI and other common pressure units: multiply by 6,894.757 to get pascals, divide by 1,000 for kilopascals, divide by 1,000,000 for megapascals, divide by 100,000 for bar, divide by 101,325 for standard atmospheres, and divide by 133.322 for millimetres of mercury (mmHg).
Note that PSI here is absolute pressure (psia). Gauge pressure (psig), as read by a tyre gauge or pressure gauge, is the pressure above local atmospheric pressure (≈ 14.696 psi at sea level). To convert gauge to absolute, add 14.696 psi. This calculator does not account for ambient pressure — for gauge pressure scenarios, use the result as a pressure difference above zero.
Frequently asked questions
PSI simply means pounds per square inch. Psia (PSI absolute) is total pressure measured from a perfect vacuum. Psig (PSI gauge) is pressure above local atmospheric pressure (≈ 14.696 psia at sea level). A car tyre rated at 32 psig is actually at 32 + 14.7 ≈ 46.7 psia. This calculator gives absolute pressure.
The weight of an object in pounds equals the force it exerts under standard gravity, so PSI = weight (lb) ÷ contact area (in²). A 200 lb person standing on both feet (contact area ≈ 20–30 in²) exerts roughly 7–10 PSI on the floor.
Car tyre: 28–36 psi; bicycle road tyre: 80–130 psi; garden hose: 40–80 psi; fire hose: 100–300 psi; hydraulic systems: 1,000–5,000 psi; human blood pressure: 1.5–2.4 psi (80–120 mmHg). Atmospheric pressure at sea level is 14.696 psia.
Also known as
TG we-Calculate Editorial Team. (2026). Pounds Per Square Inch (PSI) Calculator — Force & Area to Pressure [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/pounds-per-square-inch-calculator
TG we-Calculate Editorial Team. "Pounds Per Square Inch (PSI) Calculator — Force & Area to Pressure." TG we-Calculate. 2026. https://we-calculate.com/calculator/pounds-per-square-inch-calculator.
TG we-Calculate Editorial Team, "Pounds Per Square Inch (PSI) Calculator — Force & Area to Pressure," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/pounds-per-square-inch-calculator
@misc{wecalculate_pounds_per_square_inch_calculator, title = {Pounds Per Square Inch (PSI) Calculator — Force & Area to Pressure}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/pounds-per-square-inch-calculator}}, year = {2026}, note = {TG we-Calculate} }
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