Charles's Law Calculator: V1 / T1 = V2 / T2

How the volume of a gas changes with temperature at a constant pressure.

Calculated from standard textbook formulas, with every step shown. The formulas are fixed, so the working does not need checking: what matters is the numbers you type in. Use these calculators only if you are competent to choose the inputs (loads, material strength, dimensions, supports) and check your units and assumptions. For learning and checking your own working: design and sign-off are for a qualified engineer. Drafting Central does not store the numbers you type.

How this calculator works

Choose which quantity you want to find.

Enter the other values in the units shown.

The calculator gives the answer with the formula, the substituted numbers, and the answer in other units.

Formulas used

  • \frac{V_1}{T_1} = \frac{V_2}{T_2}
  • V_2 = V_1\frac{T_2}{T_1}

Worked example

With the default numbers in the calculator above:

  1. The formula, arranged to find the final volume: final volume = (starting volume x final temperature) / (starting temperature)
  2. Put the values in (every value in its SI unit): final volume = (2 x 350) / (300)
  3. The answer: final volume: 2.33333 L
  4. The same answer in other units: 2333.33 mL; 0.00233333 m3

Change the numbers in the calculator to see the full working, every step, for your own case.

Common questions

What is Charles's law?

For a fixed amount of gas at constant pressure, the volume divided by the absolute temperature stays constant.

Why must I use kelvin?

The law uses absolute temperature, and degrees Celsius have an arbitrary zero.

How do I convert Celsius to kelvin?

Add 273.15.

Related calculators

Got a question about this? Ask an engineering question and get a plain-language answer with references.

Further reading: Any physics or chemistry text (the gas laws).

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