Ideal Gas Law Calculator
Choose the unknown and enter the other three gas properties.
Your numbers
Your results
Ideal Gas Law Calculator by TheCalcTools
How the Ideal Gas Law Calculator works
Pick the quantity you want to find and fill in the other three.
Pressure is in kilopascals, volume in litres, temperature in kelvin.
With these units the gas constant is 8.314 J/(mol·K), as kPa × L equals joules.
The formula
Worked example
Using the default values shown in the calculator:
| Solve for | Pressure |
|---|---|
| Pressure (kPa) | 101.325 |
| Volume (L) | 22.414 |
| Amount (mol) | 1 |
| Temperature (K) | 273.15 |
- One mole of gas at 273.15 K occupies 22.414 L at 1 atm.
- P = nRT ÷ V = 1 × 8.3145 × 273.15 ÷ 22.414 = 101.325 kPa.
Result:
| Pressure (kPa) | 101.325 |
|---|---|
| Volume (L) | 22.414 |
| Amount (mol) | 1.0000 |
| Temperature (K) | 273.15 |
| Temperature (°C) | 0.00 |
Frequently asked questions
What is an ideal gas?
One whose particles do not interact and take up no volume. Real gases behave this way at low pressure and moderate temperature.
Why must temperature be in kelvin?
The law relates pressure and volume to absolute temperature. Add 273.15 to a Celsius value.
Sources and further reading
Related calculators
More in Physics · All calculators
This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.