Boyle's Law Calculator
Pressure and volume at constant temperature.
Enter your values
Enter the initial pressure in atm.
Enter the initial volume in L.
Enter the final volume in L.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Final pressure
- 2.4 atm
- Pressure change
- 0.9 atm
- Volume ratio
- 1.6
- Constant P×V
- 6
Working
- 1P₂ = (1.5 × 4) ÷ 2.5 = 2.4 atm
Quick answer
At constant temperature, gas pressure and volume are inversely proportional, so P₁V₁ = P₂V₂.
P₁V₁ = P₂V₂
At a glance
| What it does | Pressure and volume at constant temperature. |
|---|---|
| Category | Science |
| Inputs needed | Initial pressure, Initial volume, Final volume |
| Main output | Final pressure |
| Formula | P₁V₁ = P₂V₂ |
| Cost | Free — no sign-up, no download |
How to use the Boyle's Law Calculator
- 1Enter the initial pressure and volume.
- 2Enter the new volume.
- 3Keep units consistent throughout.
Inputs explained
- Initial pressure(atm)
- Enter the initial pressure in atm.
- Initial volume(L)
- Enter the initial volume in L.
- Final volume(L)
- Enter the final volume in L.
Worked example
Using the values the calculator loads with:
Inputs
- Initial pressure1.5 atm
- Initial volume4 L
- Final volume2.5 L
Results
- Final pressure2.4 atm
- Pressure change0.9 atm
- Volume ratio1.6
- Constant P×V6
- P₂ = (1.5 × 4) ÷ 2.5 = 2.4 atm
Frequently asked questions
Does temperature matter?
Boyle's law assumes it is constant; otherwise use the combined gas law.
Is it exact?
It is an ideal-gas approximation — real gases deviate at high pressure.
What do I need to enter into the Boyle's Law Calculator?
Just 3 values: initial pressure, initial volume, final volume. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Boyle's Law Calculator work out the answer?
At constant temperature, gas pressure and volume are inversely proportional, so P₁V₁ = P₂V₂. It applies the formula P₁V₁ = P₂V₂ and shows the working so you can check each step by hand.
Is the Boyle's Law Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.