Estimate your energy bill
Enter annual electricity and gas usage, or use the default typical-use figures. The calculator multiplies your kWh usage by the relevant unit rate and adds each standing charge.
Annual estimate based on 365 days and typical dual-fuel usage.
How the energy bill estimate works
Energy bills have two main parts: usage charges and standing charges. Usage charges depend on how many kWh you use. Standing charges are fixed daily charges that apply even if usage is low.
electricity cost = electricity kWh × electricity unit rate + electricity standing charge
gas cost = gas kWh × gas unit rate + gas standing charge
total energy bill = electricity cost + gas costThe Ofgem energy price cap does not mean your total bill cannot go above the headline annual figure. It limits the rates used on default tariffs, so higher usage still means a higher bill.
Default rates used in this calculator
The default values are based on Ofgem average Direct Debit price cap figures for England, Scotland and Wales for 1 July to 30 September 2026.
| Fuel | Unit rate | Standing charge | Default annual use |
|---|---|---|---|
| Electricity | 26.11p/kWh | 57.19p/day | 2,700 kWh |
| Gas | 7.33p/kWh | 29.04p/day | 11,500 kWh |
Your exact tariff may be different. Check your latest bill for your own rates, standing charges and annual consumption.
What affects your energy bill?
Your bill changes when usage, unit rates, standing charges, payment method, meter type or household habits change.
- Usage: heating, hot water, cooking, appliances and insulation all affect kWh.
- Unit rate: this is the price per kWh for electricity or gas.
- Standing charge: this is the daily charge for being connected to the network.
- Tariff type: a standard variable tariff and a fixed energy tariff can behave differently.
- Meter type: Economy 7 or smart-meter data can change how you understand usage.
What to do after estimating your bill
Once you know the rough bill, the next step is to find where the cost is coming from and what can reduce it.
Compare energy-saving options
If your bill looks high, you may want to compare tariffs, appliance usage, insulation, heating upgrades or solar options. Calculatorz estimates are designed to help you understand the numbers before requesting quotes.
Compare energy-saving options
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Energy bill estimator FAQs
How do I estimate my energy bill?
Multiply electricity and gas usage by their unit rates, then add the daily standing charges for the selected period.
Does the price cap mean my bill cannot go above the headline figure?
No. The headline cap is based on typical usage. If you use more energy, your bill can be higher.
Where do I find my kWh usage?
Your latest energy bill or online account usually shows annual consumption or estimated annual usage in kWh.
Can I estimate an electricity-only home?
Yes. Set gas usage and the gas standing charge to zero.