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Charles Law Calculator

Find final gas volume after a temperature change at fixed absolute pressure.

Your numbers

Free calculator
YOUR RESULT
3input volume units

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When to use this calculator

Using degrees Celsius directly in the temperature ratio would produce incorrect results.

Explore the gas laws calculators for other questions in this topic. For a related calculation, use the Combined Gas Law Calculator: Find final volume when ideal-gas pressure and temperature both change.

PUTTING IT INTO PRACTICE

Charles Law: a worked example

The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.

Example inputs and calculated result
InputExample value
Initial volume2
Initial temperature (K)300
Final temperature (K)450
Result3 input volume units
  1. Check the input labels and enter the example values above.
  2. Apply the relationship: Final volume = initial volume × final temperature/initial temperature.
  3. The result is 3 input volume units, rounded for display.

How to interpret your result

Temperatures must be absolute kelvins; amount of gas and pressure remain constant.

Gas-law ratios require absolute pressure and kelvin temperature. Hold the quantities specified by each law constant. Real gases can depart from ideal behaviour, especially at high pressure or low temperature.

A useful next step is the Density Calculator: Calculate average material density from mass and volume.

Frequently asked questions

Can I enter Celsius in a gas-law temperature ratio?

No. Convert to absolute temperature in kelvins first. The Celsius zero point is not absolute zero.

When is the charles law calculator useful?

Using degrees Celsius directly in the temperature ratio would produce incorrect results.

How do I use the charles law calculator?

Enter initial volume, initial temperature (k), final temperature (k). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.

Which formula does this calculator use?

Final volume = initial volume × final temperature/initial temperature.

What should I check before using the result?

Temperatures must be absolute kelvins; amount of gas and pressure remain constant.

How are results rounded?

Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.

Further reading

For background on this topic, see OpenStax: gases and the ideal gas law ↗. This is a topic reference, not an external review or endorsement of this tool.

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