Physics
Pressure from force and area
The defining relation. Divide the perpendicular force by the area that carries it, and the result is in pascals.
The Formula
P = F / A
The defining relation. Divide the perpendicular force by the area that carries it, and the result is in pascals.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| P | Pressure | pascals | Force per unit area, in pascals when force is in newtons and area in square metres. |
| F | Force applied perpendicular to the surface | newtons | Measured in newtons; only the component perpendicular to the surface counts. |
| A | Contact area | square metres | In square metres. Halving it doubles the pressure for the same force. |
What Each Symbol Means
Ppascals
Pressure
Force per unit area, in pascals when force is in newtons and area in square metres.
Fnewtons
Force applied perpendicular to the surface
Measured in newtons; only the component perpendicular to the surface counts.
Asquare metres
Contact area
In square metres. Halving it doubles the pressure for the same force.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate pressure page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Pressure, filed under Science. Every number the guide produces comes from substituting into this one line.