ChemBench

Boyle's Law Calculator

Squeeze the volume, the pressure rises.

Initial pressure (atm)

Initial volume (L)

Final volume (L)

Final pressure

2 atm

P₁V₁ = P₂V₂

What you entered

Initial pressure (atm): 1Initial volume (L): 10Final volume (L): 5

1
P₂ = P₁V₁ ÷ V₂
(1 × 10) ÷ 5= 2

Result

Final pressure: 2 atm

Compressing to 5L raises the pressure to 2 atm.

Boyle's law: pressure against volume at fixed temperature

P1V1 = P2V2. Squeeze a gas into half the volume and the pressure doubles, as long as temperature stays constant.

Initial pressure	Initial volume	New volume	New pressure
1 atm	10 L	5 L	2.000 atm
1 atm	10 L	20 L	0.500 atm
1 atm	1 L	0.5 L	2.000 atm
1 atm	22.4 L	11.2 L	2.000 atm
2 atm	6 L	3 L	4.000 atm
5 atm	2 L	10 L	1.000 atm

This is why a diver's lungs are at risk on a fast ascent: halving the ambient pressure doubles the volume of any trapped air.

Pressure and volume move in opposite directions

At constant temperature, compressing a gas into a smaller volume forces its pressure up proportionally — P₁V₁ = P₂V₂ captures this inverse relationship exactly.

Everyday Boyle's Law

A syringe with the tip blocked, a bicycle pump, and the way your lungs work when you breathe all rely on this exact relationship between squeezed volume and rising pressure.

Frequently asked questions

A gas at 2.0 atm occupies 5.0 L — what is the pressure if compressed to 2.0 L at the same temperature?

P2 = P1V1/V2 = 2.0 × 5.0 / 2.0 = 5.0 atm. Cutting the volume by 60% raises pressure by the same factor.

How is Boyle's law different from the ideal gas law?

Boyle's law is a special case of PV = nRT where temperature and moles are held constant. Use the ideal gas law calculator when temperature or moles also change.

Does Boyle's law work for liquids?

No. Liquids are nearly incompressible, so their volume barely changes with pressure. Boyle's law applies only to gases, which are highly compressible.