Mass from gas properties
Ideal Gas Mass Calculator
Calculate the mass of a gas sample when its absolute pressure, volume, molar mass, and temperature are known.
INTERACTIVE CALCULATOR
Calculate gas mass
Enter the gas properties to calculate the sample mass in grams.
Understand the science
Gas mass formula
The ideal gas law gives the number of moles. Multiplying that amount by molar mass yields the gas sample's mass.
The formula
m = PVM / RT
Assumptions and conditions
- The gas is approximated as an ideal gas.
- Pressure is absolute pressure in kPa.
- Volume is in litres, molar mass in g/mol, and temperature in Kelvin.
Frequently asked questions
How do I calculate gas mass?
Use m = PVM/(RT) with consistent units and absolute temperature.
What is the output unit?
The result is returned in grams.
Why must pressure be absolute?
The ideal gas equation uses absolute pressure rather than gauge pressure.
Why is temperature entered in Kelvin?
Kelvin is the absolute temperature scale used by the ideal gas equation.
How to use this calculator
- Enter absolute pressure in kPa.
- Enter the gas volume in litres.
- Enter molar mass in g/mol.
- Enter temperature in Kelvin.
- Select Calculate mass to display the result.
Understanding the result
The result is the estimated gas mass in grams. The calculation assumes ideal-gas behaviour and uses the gas constant in kPa·L/(mol·K).