Charles's Law Calculator
Calculate the final volume of a gas when its temperature changes while pressure and the amount of gas stay constant. Enter temperatures in Kelvin.
Charles's law
Find final volume at constant pressure.
Enter positive values. Temperatures must be in Kelvin and pressures must be absolute, not gauge pressure.
Your answer will appear here
Enter your known values and select Calculate to see the result, formula, and solution steps.
How Charles's law works
Charles's law describes the relationship between gas volume and absolute temperature at constant pressure. As the temperature rises, the gas volume increases proportionally under the law's assumptions.
V₁ / T₁ = V₂ / T₂
Assumptions and conditions
- Pressure and the amount of gas remain constant.
- Temperatures must be entered in Kelvin.
- Initial and final volumes must use the same unit.
Frequently asked questions
What is Charles's law?
Charles's law states that a gas's volume is directly proportional to its absolute temperature when pressure and amount of gas remain constant.
Why is Kelvin required?
Kelvin is an absolute temperature scale, so it can be used in gas-law ratios without an arbitrary zero offset.
What happens when temperature increases?
At constant pressure, increasing the absolute temperature increases the volume of the gas in proportion.
What is the formula for Charles's law?
The formula is V₁/T₁ = V₂/T₂. Rearranging it gives V₂ = V₁T₂/T₁.
How to use this calculator
- Enter the initial gas volume.
- Enter the initial temperature in Kelvin.
- Enter the final temperature in Kelvin.
- Select Calculate result to find the final volume.
Charles's law formula
The equation V₁/T₁ = V₂/T₂ relates the volume and absolute temperature of a gas at constant pressure. Rearranging the equation gives V₂ = V₁T₂/T₁ for calculating the final volume.