Combined Gas Law
Find final pressure, volume, or temperature with the combined gas law. Includes algebra steps and consistent-unit guidance for gas-law problems. Free online calculator with formulas and step-by-step solutions.
Key formula
(P1V1)/T1 = (P2V2)/T2
About this tool
The combined gas law links two states of the same gas sample: P₁V₁/T₁ = P₂V₂/T₂. This page keeps the ratio visible so you can solve for final pressure, volume, or temperature without losing the Kelvin and unit checks that usually cost marks.
How to use this calculator
- Choose the variable you want to solve for and confirm which values are already known.
- Enter inputs in consistent units before calculating so the formula is applied correctly.
- Check whether the result is physically reasonable by comparing it with the size of the inputs.
- Use the step-by-step breakdown to see how the equation was rearranged and evaluated.