Gas bill terminology
The measurements, rates and industry terms you are most likely to meet on a UK gas bill.
- Calorific value
- A measure of how much energy the gas contains. It varies slightly by location and time and is shown in megajoules per cubic metre (MJ/m³) on most bills.
- Effective unit rate
- The whole bill—including fixed charges—divided by the energy used. For example, a £40 bill for 400 kWh has an effective rate of 10p per kWh. It includes fixed charges, so it differs from your tariff’s unit rate.
- Estimated reading
- A reading calculated by the supplier when it does not have an actual meter reading. It is usually marked with an E on a bill.
- Imperial meter
- An older meter that records gas in hundreds of cubic feet (ft³). Its units must be converted to cubic metres before the kWh calculation.
- Kilowatt hour (kWh)
- A unit of energy equal to 1,000 watt-hours. Gas tariffs charge by kWh even though the meter itself measures volume. A 2 kW appliance running for one hour uses 2 kWh of energy.
- Metric meter
- A meter that records gas volume in cubic metres (m³).
- Energy price cap
- The maximum unit rates and standing charges suppliers can apply to default tariffs. Ofgem reviews it every three months. It does not limit the total amount a household can be billed.
- Standing charge
- A fixed daily charge for being connected to the gas supply, whether or not any gas is used that day.
- Unit rate
- The price paid for each kWh of gas, normally shown in pence per kWh.
- VAT
- Value Added Tax. Domestic gas is currently charged at the reduced rate of 5%.
- Volume correction factor
- A standard adjustment for the effect of temperature and pressure on gas volume. A typical bill uses 1.02264.