Boyle's & Gay-Lussac's Law Calculator
Calculate final pressure using Boyle's Law (constant T) or Gay-Lussac's Law (constant V).
Assumptions used in this calculation
- Ideal gas, other variable held constant: Assumes ideal gas behavior and that the non-selected variable (temperature for Boyle's, volume for Gay-Lussac's) is truly held constant between states.
About this calculator
Boyle's Law and Gay-Lussac's Law both describe how a gas's pressure changes under a specific constraint, constant temperature for Boyle's, constant volume for Gay-Lussac's, but mixing them up, or forgetting to convert temperature to kelvin, is a common way to get a wrong or even negative pressure result. This calculator lets you pick which law applies to your scenario, then solves the corresponding proportional relationship: P₁V₁ = P₂V₂ for a gas being compressed or expanded at constant temperature, or P₁/T₁ = P₂/T₂ for a sealed, fixed-volume container being heated or cooled. It's built for physics and chemistry students working through gas-law problems, or anyone estimating what happens to pressure inside a sealed container (like an aerosol can left in a hot car, which follows Gay-Lussac's Law) or a compressed gas cylinder, without needing to remember which formula applies to which scenario or manually cross-multiply the ratios.
Worked example
Boyle's: 1atm, 10L compressed to 5L
Result: 2 atm
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