Pressure Calculator
Calculate pressure from force and area using P = F / A. Enter force in newtons and area in square metres to get pressure in pascals (Pa). Covers mechanical pressure in pistons, tyres, and structural loading scenarios.
How to use this tool
- Enter force (f) and area (a) in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your pressure and the full breakdown beneath it.
Formula
P = F / A
How it works
Pressure P is the force F acting perpendicular to a surface divided by the area A of that surface. The SI unit is the pascal (1 Pa = 1 N/m²).
Worked examples
Heel on floor
Atmospheric pressure check
Common mistakes to avoid
- Entering area in square centimetres instead of square metres — 1 cm^2 = 0.0001 m^2, so neglecting this conversion overstates area and understates pressure by a factor of 10,000.
- Confusing gauge pressure (above atmospheric) with absolute pressure (above zero) — this calculator returns absolute mechanical pressure from force and area, not gauge or differential pressure.
- Dividing the area by the force instead of the force by the area, inverting the result.
Key terms
Frequently asked questions
- What is the difference between pascals, bar, and psi?
- 1 bar = 100,000 Pa. 1 psi (pound per square inch) = 6,894.76 Pa. The pascal is the SI unit; bars and psi are common in industry and tyre pressure contexts.
- How do I calculate pressure if the force is not perpendicular to the surface?
- Only the component of force perpendicular (normal) to the surface creates pressure. Use F_perp = F * cos(theta), where theta is the angle between the force vector and the surface normal, then P = F_perp / A.
- What is a practical example of using P = F/A?
- A hydraulic jack applies a small force over a small piston area to create high pressure, which then acts over a large piston area to lift a heavy load. P = F_small / A_small = F_large / A_large illustrates Pascal's principle.