Combined Gas Law: Double Pressure, Half Volume (Same Temperature)
When pressure doubles at constant temperature, volume halves — a classic Boyle's Law demonstration via the combined gas law.
How to use this tool
- Enter initial pressure p₁, initial volume v₁, initial temperature t₁, final pressure p₂, final volume v₂ and final temperature t₂ in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your final pressure p₂ and the full breakdown beneath it.
This example shows that doubling the pressure of a gas at constant temperature cuts its volume exactly in half, consistent with Boyle's Law.
Frequently asked questions
- How is this different from the ideal gas law?
- The combined gas law relates two states of the same gas sample without needing to know the moles or R. The ideal gas law (PV=nRT) gives absolute values.
- What is Boyle's Law?
- Boyle's law is the special case where T is constant: P₁V₁ = P₂V₂.