Pick what you want to solve for — P₁, V₁, P₂, or V₂ — then fill in the other three values with your chosen pressure and volume units, and this Boyle's Law Calculator gives you the missing variable along with the formula used and its unit.
Result
--
Unit
--
Formula Used
--
Boyle's Law states that the pressure and volume of a gas are inversely proportional at constant temperature. As pressure increases, volume decreases proportionally, following the formula P₁V₁ = P₂V₂.
Use the formula P₁V₁ = P₂V₂. Enter any three known values (initial pressure, initial volume, final pressure, or final volume) and the calculator will solve for the fourth unknown variable.
Boyle's Law applies to scuba diving (pressure changes with depth), syringes, pneumatic systems, weather balloons, and any situation where gas pressure and volume change at constant temperature.
Boyle's Law is called an isothermal process because it describes gas behavior at constant temperature. 'Isothermal' means equal temperature, which is a key condition for this law to apply.
If volume is halved while temperature stays constant, pressure doubles. With initial pressure of 1 atm, the final pressure would be 2 atm, following the inverse relationship in Boyle's Law.
At cruising altitude (lower atmospheric pressure), the balloon will expand significantly. The exact expansion depends on the pressure difference, calculated using P₁V₁ = P₂V₂ with known altitude pressure values.