We understand energy bills can be confusing, but we want to make your bill as simple as we can. We’ve broken down how your bill is calculated, and have provided clear explanations on each section so you can understand your bill better.
If you would like to view an easier to understand version of your bill you can view your simple bill here, or keep reading if you would like to understand your bill in full.
Calculating your electricity charge
We charge electricity in kWh (kilowatt-hrs). To convert electricity units to kWh we use the following calculation: electricity units used x price per unit = electricity units expressed in kWh
The value of your electricity units used, and the price per unit will be on your bill.
Calculating your gas charge
We charge gas in kWh (kilowatt-hrs). To convert gas units to kWh we use the following calculation: gas units used x calorific value x volume correction / 3.6 = gas units expressed in kWh
The value of your gas units used, volume correction figures and the calorific value will be on your bill.
Typically, a gas supply has a calorific value which can vary in different parts of the country, due to the different gas sources.
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 how to read your gas and electricity meters support page.
kWh stands for kilowatt hour. It's a measure of the amount of energy used in one hour. For example, 1 kWh is the energy used by a 1,000-watt appliance running for an hour.
Different appliances consume energy at varying rates – One kWh is enough to power a 100-watt lightbulb for 10 hours, but a fridge-freezer is expected to use 1 kWh within 26 hours.*
* Figures from Ofgem 2024
A standing charge is a fixed daily fee that most energy customers pay to connect to a supply, maintain the energy supply networks, take meter readings, cover the cost of dealing with failed energy suppliers and cover customer support - these are costs that don’t vary with energy consumption.
No matter how much energy you use, your standing charge will stay the same and is a daily amount added to your overall energy costs. However, if you’re a Pay As You Go customer, the standing charge will be collected as a fixed weekly amount from your meter.
Even if you use no electricity or gas, including if your home is lying empty you still need to pay the standing charge. Similarly, if you’re a Pay As You Go customer and don’t use any gas over summer, your meter will continue to collect your standing charge. This means that if you’re a low user of gas and electricity, your standing charge could make up most of your bill.
For more information go to our standing charge webpage.
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. The CV of the gas at each local distribution zone is measured by the National Grid. They provide us with a daily value, and, from this, we work out an average for the period covered by your bill. You should be able to find this figure on your last gas bill, along with the other figures needed for your gas calculation.
The bill period is the period of time between bills/statements, this time period is covered by one bill. On the front of your bill, you’ll find the start and end dates of the period it covers.
Last updated: 24 October 2024