We charge for the number of kilowatt hours of gas that you use. If you gas meter measures your usage in cubic feet or cubic meters then we have to convert this into kilowatt hours. This is standard practice for all energy suppliers.

We include the industry formula for this calculation in your bill, and is as follows:

- If your gas meter measures your usage in cubic feet then we multiply the volume of gas used by 2.83 to convert this to cubic meters. If you have a newer meter that measures in metric units then we skip this step.
- Once you have your usage in cubic meters we need to correct for temperature and pressure as gases are affected by these. To do this we multiply the cubic meters by 1.02264.
- Next we need to consider the energy content of the gas which is the calorific value shown in your statement. We multiply by this to give the energy used in joules.
- We then convert joules to kWh's by dividing the number by 3.6.