This is a tool that calculates the change in volume or absolute temperature of a fixed mass of gas, if the pressure is held constant, using Charles' Law.

The tool is multi-directional and, therefore, determines which temperature or volume needs to be calculated based on which data has been entered. The most typical scenario is to enter an initial volume and temperature and either the final volume or temperature, and calculate the other one. However, it is also possible to calculate either the initial volume or temperature from the entered final values. After one of the volume or temperature fields has been calculated, further data changes result in the re-calculation of the same field unless that field is itself changed or a different volume or temperature is cleared.

In more detail, the information that can be entered and/or calculated is:

• The initial volume of the gas. This does not need to be in any specific unit but should be the same as the final volume unit, if entered.
• The initial absolute temperature of the gas, in kelvin.
• The final volume of the gas. This does not need to be in any specific unit but should be the same as the initial volume unit, if entered.
• The final absolute temperature of the gas, in kelvin.

Associated tool link: http://www.coggit.com/tools/charles_law_calculator.html