Calculate your gas and electricity bill
This UK energy bill calculator estimates the cost of electricity and gas from the figures that actually drive a household energy bill: usage in kilowatt hours (kWh), the unit rate for each fuel and the daily standing charge. It then converts the total into annual, monthly, weekly and daily estimates.
If you know the rates on your tariff, enter those for the most relevant estimate. If you do not, the quick-start control can load Ofgem's current average Direct Debit price-cap rates for England, Scotland and Wales as a reference point.
Current Ofgem reference rates
For 1 July to 30 September 2026, Ofgem's average Direct Debit price-cap rates across Great Britain are 26.11p/kWh for electricity with a 57.19p/day electricity standing charge, and 7.33p/kWh for gas with a 29.04p/day gas standing charge.
These are national averages, not a single tariff that applies everywhere. Actual capped rates vary by region, payment method and meter type. Fixed tariffs can also use different prices. The Ofgem price cap limits unit rates and standing charges on eligible default tariffs; it does not cap the total amount a household can pay, because the bill still rises with usage.
Don't know your annual energy usage?
The quick presets use Ofgem's Typical Domestic Consumption Values (TDCVs), updated from 1 July 2026. For standard single-rate electricity meters, the low / medium / high electricity references are 1,600 / 2,500 / 3,800 kWh per year. The equivalent gas references are 6,000 / 9,500 / 14,000 kWh per year. These are illustrative reference values, not targets for an individual home.
How the energy bill calculation works
Electricity usage cost is annual electricity kWh multiplied by the electricity unit rate. Gas is calculated in the same way. Daily standing charges are multiplied by the number of days selected, then all four components are added together.
The monthly result is an annualised average rather than a prediction of one specific month's consumption. Real winter bills can be much higher than summer bills, especially where gas is used for heating, and supplier Direct Debit payments may be smoothed across the year.
Great Britain and Northern Ireland
Ofgem's domestic energy price cap applies in England, Scotland and Wales, not Northern Ireland. The calculator itself can still be used for Northern Ireland if you enter the unit rates and standing charges from your own supplier; just do not treat the Ofgem preset as a Northern Ireland tariff.
What this estimator does not include
- Account credit or debit balances
- Debt repayment arrangements
- Supplier-specific discounts, rewards or add-ons
- Tariff changes part-way through the year
- Separate peak/off-peak Economy 7 calculations
Sources and review date
Current price-cap reference rates: Ofgem — Energy price cap unit rates and standing charges. Typical usage presets: Ofgem — Review of Typical Domestic Consumption Values.
Reviewed: 11 August 2026. Ofgem reviews the price cap every three months, so check your supplier tariff for the rates that actually apply to you.