Ideal Gas Law Calculator

Apply the ideal gas law to find pressure, volume, temperature or amount of gas.

About Ideal Gas Law Calculator

The ideal gas law relates all four state variables. At standard temperature and pressure one mole occupies 22.4 litres, which is the figure the defaults reproduce. Real gases deviate from ideal behaviour at high pressure and low temperature, where intermolecular forces and molecular volume stop being negligible.

Formula

Ideal Gas Law

p V = n R T, with R = 8.314 J/mol·K

n: Amount of substance in moles
R: Universal gas constant

Worked example

With the default values below, Ideal Gas Law Calculator returns Amount of Gas of 0.99938. Change any input above and every figure here is recalculated in your browser.

Inputs used

Pressureminimum 0.01 Pa: 101,325 Pa
Volumeminimum 0 m3: 0.0224 m3
Temperatureminimum -272 C: 0 C
Molar mass of the gasminimum 0.01 g/mol: 28.97 g/mol

Results

Amount of Gas: 0.99938 mol
Mass of Gas: 28.9519 g
Gas Density: 1.29250 kg/m3
Molar Volume at These Conditions: 0.022414 m3/mol
Temperature: 273.15 K

Step by step

1Values used
2Ideal Gas Law
3Amount of Gas= 0.99938 mol
4Mass of Gas= 28.9519 g
5Gas Density= 1.29250 kg/m3
6Molar Volume at These Conditions= 0.022414 m3/mol
7Temperature= 273.15 K

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 6 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Ideal Gas Law calculated?

p V = n R T, with R = 8.314 J/mol·K The ideal gas law relates all four state variables. At standard temperature and pressure one mole occupies 22.4 litres, which is the figure the defaults reproduce.

Why does Ideal Gas Law matter?

Real gases deviate from ideal behaviour at high pressure and low temperature, where intermolecular forces and molecular volume stop being negligible.

What values do I need to enter?

This calculator takes 4 inputs: Pressure, Volume, Temperature, Molar mass of the gas. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.