Combined Gas Law Calculator
Solve P₁V₁/T₁ = P₂V₂/T₂ for any missing value.
Enter your values
ⓘ Live results
Results
- Answer
- 1.25155 L
- Final pressure
- 2 atm
- Final volume
- 1.25155 L
- Final temperature
- 100 °C (373.15 K)
- Initial temperature in Kelvin
- 298.15 K
- PV/T constant
- 0.006708
Quick answer
The combined gas law links pressure, volume and temperature for a fixed amount of gas: P₁V₁ ÷ T₁ = P₂V₂ ÷ T₂, with temperature in Kelvin.
P₁V₁ ÷ T₁ = P₂V₂ ÷ T₂
How to use the Combined Gas Law Calculator
- 1Pick which final value you are solving for.
- 2Enter the initial pressure, volume and temperature in °C.
- 3Enter the two known final values — the third is calculated.
Worked example
Using the values the calculator loads with:
Inputs
- Solve forFinal volume V₂
- Initial pressure P₁1 atm
- Initial volume V₁2 L
- Initial temperature T₁25 °C
- Final pressure P₂2 atm
- Final volume V₂1 L
- Final temperature T₂100 °C
Results
- Answer1.25155 L
- Final pressure2 atm
- Final volume1.25155 L
- Final temperature100 °C (373.15 K)
- Initial temperature in Kelvin298.15 K
- PV/T constant0.006708
Frequently asked questions
Why must temperature be in Kelvin?
The gas laws are ratios, and only an absolute scale makes 'twice the temperature' mean twice the molecular energy.
What if the gas amount changes?
Then you need the ideal gas law PV = nRT, which includes moles explicitly.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.