Gas Pressure Calculator

Calculate gas pressure using the ideal gas law. Enter gas amount, volume, and temperature to estimate pressure in PSI, kPa, pascals, bar, atmospheres, mmHg, and inches of water column.

Calculate Gas Pressure

Ideal Gas Law: P = nRT ÷ V
Your result will appear here.

How the gas pressure calculator works

Gas amount:
Enter the amount of gas in moles, millimoles, or kilomoles.

Volume:
Enter the container volume. A smaller volume creates higher gas pressure for the same amount and temperature.

Temperature:
Enter the gas temperature. The calculator converts it to Kelvin for the pressure formula.

Why use a gas pressure calculator?

A gas pressure calculator is useful for chemistry examples, ideal gas law practice, sealed containers, lab calculations, gas tanks, pressure conversions, and comparing absolute pressure to gauge pressure.

This calculator uses the ideal gas law, so real gases can vary at high pressure, very low temperature, or unusual conditions.

Gas pressure formula

The ideal gas pressure formula is:

P = nRT ÷ V

Gas pressure calculator tips

Frequently asked questions

How do you calculate gas pressure?

Use the ideal gas law: P = nRT ÷ V. Multiply moles by the gas constant and temperature, then divide by volume.

What is the difference between absolute and gauge gas pressure?

Absolute pressure is measured from a vacuum. Gauge pressure is pressure above atmospheric pressure.

Does gas pressure increase with temperature?

Yes. If gas amount and volume stay the same, increasing temperature increases gas pressure.

Does gas pressure increase when volume decreases?

Yes. If gas amount and temperature stay the same, reducing volume increases gas pressure.