Pressure Calculator

Last updated: June 2026

Mode

Force

Force unit

Area

m²

Area unit

Pressure

100,000 Pa

kPa

100 kPa

bar

1 bar

psi

14.504 psi

atm

0.987 atm

Formula

Pressure = force / area. Force = pressure x area. Area = force / pressure.

Pressure references

Example	Typical pressure
Car tyre	30-35 psi / 2.0-2.4 bar
Atmosphere	1 atm = 14.7 psi
Blood pressure	120/80 mmHg
Bicycle tyre	100-120 psi

About this calculator

The Pressure Calculator calculates pressure, force, or area using the relationship between force and surface area. It supports practical unit conversions such as pascals, kilopascals, bar, psi, atmospheres, square metres, square centimetres, and square inches.

Pressure formula

Pressure is force spread over an area. The same force creates higher pressure when applied to a smaller area.

pressure = force / area
force = pressure x area
area = force / pressure

How to use the pressure calculator

Choose whether to find pressure, force, or area.
Enter the two known values.
Select the correct force, area, and pressure units.
Use psi or bar for tyre-style examples and pascals for SI physics.
Review the main answer and common equivalent pressure units.
Check the reference values for context.

Worked examples

Force over a plate

Input: Force 1,000 N, area 0.5 m2

Calculation: P = 1,000 / 0.5

Result: 2,000 Pa

Atmospheric pressure reference

Input: 1 atmosphere

Calculation: 1 atm = 101,325 Pa

Result: About 1.013 bar or 14.7 psi

Useful pressure references

Reference	Approximate pressure
1 atm	101,325 Pa
1 bar	100,000 Pa
1 psi	6,894.76 Pa
Typical car tyre	30-35 psi

Why area changes pressure

A sharp object can create high pressure with modest force because the contact area is small. A wide support spreads the same force over more area and lowers pressure.

Pressure calculation limits

This is a general calculation tool. Do not use it as safety guidance for tyres, gas cylinders, medical equipment, pressure vessels, or structural design.

Frequently asked questions

What is pressure measured in?

The SI unit is the pascal, but bar, psi, atm, and mmHg are also common.

How do I find force from pressure?

Multiply pressure by area.

Why does smaller area mean higher pressure?

Because the same force is concentrated over less surface area.

Is bar the same as atm?

No. They are close, but 1 atm is 101,325 Pa while 1 bar is 100,000 Pa.

Can I use this for tyre pressure?

You can convert units, but always follow the vehicle manufacturer recommended tyre pressure.

Related calculators

Force Calculator
Area Calculator
Concrete Calculator

What does this mean?

This calculator is designed to help you understand the likely number before you make a decision or start an application.

Your result should be checked against official UK guidance, especially if your circumstances include dependants, exemptions, prior leave, or a complex immigration history.

Treat the figure as a planning tool rather than legal advice. Where the answer affects an application deadline or major payment, speak to an authorised adviser.