Pressure Calculator

1. Enter any two of pressure, force and area.
2. Leave the one you want to find blank.
3. Read the result.
4. See which value was solved for and the formula used.

Here is what each result means:

Pressure is how concentrated a force is over the area it presses on. The same push spread over a small area makes a high pressure, while spread over a large area it makes a low one. That is why a sharp knife cuts and a wide snowshoe keeps you on top of the snow: the force is similar, but the area is very different.

In SI units pressure is measured in pascals, where one pascal is one newton acting on one square meter. Because a pascal is small, everyday pressures are often given in kilopascals or bars, and tyre pressures in pounds per square inch. This calculator works in the base SI units, so keep force in newtons and area in square meters for a result in pascals.

Pressure acts in all directions in a fluid and always pushes at right angles to a surface. It underlies weather systems, hydraulics, breathing and the crush of the deep sea. Whenever a force is shared across a surface, dividing the force by the area tells you how hard the surface is being pressed at each point.

It rearranges one relation to solve for whichever value you leave blank.

1. For pressure, divide force by area.
2. For force, multiply pressure by area.
3. For area, divide force by pressure.

Pressure builds on force; see the force calculator and density calculator.

A force of 100 newtons presses on an area of 2 square meters.

Calculation: P = F / A = 100 / 2 = 50 pascals. To find the force needed for a pressure of 200 pascals over 5 square meters, multiply: 200 times 5 is 1000 newtons.

One relation, rearranged for whatever you need to find.

All three come from P equals F over A, so any two of the values give the third. This makes the pressure rule easy to apply to a load on a floor, a piston in a cylinder or a column of water, as long as the force is spread evenly over the area.

Pressure is quoted in several units, which can cause confusion.

This calculator works in pascals, so convert other units first. For example, 2 bar is 200,000 pascals, and standard atmospheric pressure is about 101 kilopascals, or the weight of the air pressing down on every square meter at sea level.

The Force

A bigger force on the same area gives more pressure, in direct proportion.

The Area

Spreading the same force over a larger area lowers the pressure. Halving the area doubles the pressure.

The Shape of Contact

A sharp point concentrates force into a tiny area, producing a very high pressure from a modest force.

Physics Homework

Solve for pressure, force or area in a mechanics problem.

Engineering

Check the load a surface, foundation or piston must bear.

Everyday Questions

Compare how footwear, tyres or tools spread a force over a surface.

1. Wrong Area Units

Area must be in square meters for a result in pascals. Convert square centimeters first.

2. Confusing Force and Pressure

Force is the total push in newtons; pressure is that push per square meter.

3. Using Weight Loosely

A weight in kilograms is not a force. Multiply mass by gravity to get newtons first.

4. Mixing Pressure Units

Convert bar, psi or atmospheres to pascals before entering values.

5. Zero Area

Solving for pressure cannot divide by an area of zero.

The relation is exact; only the displayed decimals are rounded.

Pressure is how concentrated a force is over the area it acts on. It equals force divided by area. A force of 100 newtons on 2 square meters gives a pressure of 50 pascals.

Divide the force by the area. If 100 newtons press on 2 square meters, the pressure is 100 divided by 2, which is 50 pascals.

Multiply the pressure by the area. Leave the force field blank and enter pressure and area, and the calculator solves for it.

Divide the force by the pressure. Leave the area field blank and enter pressure and force to solve for the area.

A pascal is the SI unit of pressure, equal to one newton spread over one square meter. It is small, so pressures are often given in kilopascals or bars.

One bar is 100,000 pascals and one psi is about 6,895 pascals. Convert to pascals before entering values, since this calculator works in SI base units.

Because it concentrates the force into a very small area. Since pressure is force divided by area, a tiny area gives a large pressure even from a modest force.

Use newtons for force and square meters for area to get pressure in pascals. Keep the units consistent for a correct result.

No. The calculation runs in your browser and nothing you enter is stored or sent anywhere, unless you choose Save, which keeps the result only on this device.

• Pressure (Wikipedia).
• Pascal (unit) (Wikipedia).
• Pressure explained (Maths Is Fun).