Boyle's Law Calculator
Enter any three of initial pressure, initial volume, final pressure and final volume, and this calculator finds the fourth using Boyle's Law, P1V1 = P2V2, at constant temperature. Units are relative, so use any consistent pressure and volume units.
How to use the Boyle's Law calculator
- Pick which quantity you want to solve for.
- Enter the other three values in any consistent pressure and volume units.
- Read the missing value, solved from P1V1 = P2V2.
Examples
Solve for final pressure
P1 = 1, V1 = 10, V2 = 5
P2 = 2
Solve for final volume
P1 = 2, V1 = 3, P2 = 6
V2 = 1
Frequently asked questions
What is Boyle's Law?
Boyle's Law states that at constant temperature the pressure and volume of a fixed amount of gas are inversely proportional, so P1V1 = P2V2.
What units should I use?
Any consistent units work because only the ratio matters. Use the same unit for both pressures and the same unit for both volumes.
Does temperature need to stay constant?
Yes. Boyle's Law assumes constant temperature and a fixed amount of gas. If temperature changes, use the combined gas law instead.
How many values do I need to enter?
Exactly three of the four. From any three of P1, V1, P2 and V2 the fourth is fully determined.
Why must the values be positive?
Pressure and volume of a real gas are always greater than zero, so the calculator rejects zero or negative inputs.
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