How to Calculate Pressure in Pascals from Force and Area

Calculates pressure as P = force ÷ area. Force is in newtons, area in m², and pressure in pascals (Pa).

Explanation

Pressure tells you how concentrated a force is. The same push spread over a smaller area presses far harder.

P = \dfrac{F}{A}

$P$ is the pressure, in pascals (Pa)
$F$ is the force perpendicular to the surface, in newtons (N)
$A$ is the area the force acts on, in square metres (m²)

One pascal is one newton spread over one square metre, so 1 Pa = 1 N/m².

Example

The defaults are a force of 100 N on an area of 2 m².

P = \dfrac{100}{2} = 50\,\mathrm{Pa}

The pressure is 50 Pa. Press with the same 100 N on 0.01 m² instead, a square 10 cm on a side, and the pressure leaps to 10000 Pa. A drawing pin and a snowshoe are the same idea used in opposite directions.

Notes

Areas go in square metres. If you measured in cm², divide by 10000, because 1 m² = 10000 cm². Getting this wrong throws the answer out by four orders of magnitude.

Only the component of the force perpendicular to the surface counts. Resolve an angled push before entering it.

The area cannot be zero, since that would mean dividing by zero.

Atmospheric pressure is about 101325 Pa, or roughly 1013 hPa. 1 hPa = 100 Pa and 1 kPa = 1000 Pa; the hectopascals in a weather forecast are these same pascals.