Boyle's Law (P₁V₁ = P₂V₂)

Constant T, constant n: pressure × volume = constant.

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Result

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General calculation reads

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How to use this calculator

  • Enter P₁, V₁, P₂.
  • Read V₂.

About this calculator

Boyle's Law (1662): for fixed n, T, gas pressure × volume is constant. Doubling pressure halves volume. Demonstrated with sealed syringe — push, pressure rises, volume drops. Relevant to scuba diving (air compresses going deep), cylinders + pneumatic systems, and deep-sea creatures (collapsible body cavities).

Frequently asked

Constant T critical?+
Yes — Boyle assumes isothermal. If T changes, use combined gas law.
Why does this work?+
Kinetic theory: smaller volume means molecules collide with walls more often → higher pressure.
Real-world?+
Diving (air compresses), spray cans (push gas to release product), inflatable structures.
Failure?+
High-pressure (>50 atm) or low-temp (near liquefaction). Real gases deviate.
Inversely proportional?+
P ∝ 1/V at constant T. PV = constant. Plot P vs. V: hyperbola.

Related calculators

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Solve for any of P, V, n, T given the other three. R = 8.314 J/(mol·K).
Charles's Law (V₁/T₁ = V₂/T₂)
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Avogadro's Law (V₁/n₁ = V₂/n₂)
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Combined Gas Law (P₁V₁/T₁ = P₂V₂/T₂)
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