Ideal Gas Law Calculator
Solve PV=nRT for pressure, volume, moles or temperature.
About this tool
The ideal gas law, PV = nRT, relates a gas's pressure, volume, amount (moles) and temperature. Pick which quantity to solve for and enter the other three — uses R = 0.082057 L\u00b7atm/(mol\u00b7K).
Key Features
- Solve for pressure, volume, moles or temperature
- Uses standard atm/L/mol/K units
- Matches STP (1 mol at 273.15 K ≈ 1 atm for 22.414 L)
How to Use
- Choose which quantity to solve for.
- Enter the other three values (temperature in Kelvin).
- Click Calculate.
Benefits
- Check chemistry homework on gas laws
- Predict how changing one variable affects the others
- Verify STP relationships
Frequently Asked Questions
The ideal gas law requires an absolute temperature scale where 0 means true zero energy — Celsius or Fahrenheit have arbitrary zero points that would make the equation give wrong results. Convert Celsius to Kelvin by adding 273.15.
The ideal gas law is an approximation that works well for most gases at normal temperatures and pressures, but it becomes less accurate at very high pressure or very low temperature, where real gas behavior (like the Van der Waals equation) diverges from ideal.