Your consumption charge for electricity is calculated by multiplying the units you’ve used by the unit rate, specified as part of your tariff
For gas, the calculation is more detailed.
Multiply the number of gas units used by the Calorific Value and then the Volume Correction
Divide the answer to step 1 by 3.6 to covert into gas kilowatts used
Please note: If you have an imperial gas meter, you’ll need to multiply the gas units by 2.83 to convert imperial units to metric units before conducting the above calculation. To find out if you have an imperial meter, take a look at the meter reading guide section of our website. The Calorific Value and Volume Correction figures can be found on your bill.
Once your consumption charge has been calculated, the standing charge is added for each fuel (gas and electricity). This is a daily charge for each day of the bill period.
What does KWH stand for
kWh stands for kilowatt hour. It's a measure of the amount of energy used in one hour. For example, if you have a 1,000 watt heater and you keep it on for one hour, you'll use 1kWh
What are standing charges?
Standing charges are fixed costs of supplying customers with gas or electricity – these are costs that don’t vary with energy consumption.
Standing charges include the costs of providing and maintaining meters in customers’ homes, and customer support, along with some of the charges we pay for distributing and transporting energy.
For most customers, the standing charge is a daily rate on your bill. However, if you’re a Pay As You Go customer, the standing charge will be collected as a fixed weekly amount from your meter. To ensure tariffs are comparable across the energy market, Ofgem, the energy market regulator, requires all tariffs to have a unit rate and standing charge component
What is a bill period?
The bill period is the period of time (usually in days) covered by a particular bill. On the front of your bill you’ll find the start and end dates of the period it covers.
What is a Calorific Value?
Calorific Value (CV) is a measure of the energy contained in the gas that's provided to your home. The CV can vary in different parts of the country, due to the different sources of gas. National Grid provide us with a daily value and, from this, we work out an average for the period covered by your bill.
Last updated 29th March 2023