Energy bill calculator
Take the unit rates and standing charges off your latest bill, add your usage, and see what a full year actually costs.
How this is calculated
Each fuel is worked out the same way: usage multiplied by the unit rate, plus the standing charge multiplied by 365 days.
Standing charges are payable whether you use any energy or not, which is why a low-usage home can still face a bill of several hundred pounds a year.
Everything here is entered in pence and converted, because that is how rates appear on a bill. Enter 24.5, not 0.245.
This is a flat-rate calculation. If you are on Economy 7, a time-of-use tariff or an electric vehicle tariff, your day and night rates differ and this will not reflect that.
Rates used · 2026/27
| Typical household electricity | about 2,700 kWh a year |
| Typical household gas | about 11,500 kWh a year |
| Billing year | 365 days |
| Rates used | whatever is on your bill |
Last checked July 2026. Source: HMRC and gov.uk.
Worked example
At 24.5p per kWh with a 60p daily standing charge, 2,700 kWh of electricity costs £661.50 in units plus £219 in standing charges, so £880.50 a year. Gas at 6.2p on 11,500 kWh adds £713 in units and £116.80 in standing charges, so £829.80. Together that is £1,710 a year, about £143 a month, and £336 of it is standing charges you pay before using anything.
Common questions
Where do I find my unit rate?
On any recent bill or in your supplier account, usually labelled as pence per kWh alongside a separate daily standing charge. Both change when you switch tariff or when the price cap moves.
Why does this not use the price cap?
The cap sets a maximum for standard variable tariffs, not the rate you personally pay. Using your own figures gives an answer that is right for you and does not go stale every three months.
Does this work for Economy 7?
Not accurately. Economy 7 charges different rates for day and night, so it needs its own calculator with two rate fields.
My usage is in cubic metres, not kWh.
Older gas meters measure volume. Your bill converts it for you, so take the kWh figure from the statement rather than the meter reading.