Bills & Utilities
UK Energy Bill Calculator
Enter your electricity and optional gas usage, unit rates, standing charges, and billing period to estimate the total bill and standing-charge share.
Your details
Enter your details below
Your result
Based on the values you enter
Ofgem GB Direct Debit rate examples: 1 October to 31 December 2026; checked 14 October. Gas includes 5% VAT; electricity has no VAT for this period. Enter your own bill rates; no extra VAT is added. Comparison quotes and usage are illustrative.
Useful next checks
- Check the inputs before relying on the result.
- Try a second scenario to compare outcomes.
- Read the guide below for context.
# UK Energy Bill Calculator
Estimate a UK electricity or dual-fuel bill from your own kWh usage, unit rates, standing charges, and billing period.
What this calculator does
Enter the figures from your bill or tariff notice and the calculator adds the usage charge and daily standing charge for electricity, gas, or both fuels. It also shows monthly and annual equivalents so you can compare a short bill period with a full-year budget.
How it works
For each fuel, the estimate is:
`usage in kWh x unit rate in pence / 100 + standing charge in pence x days / 100`
The calculator then adds electricity and gas together. If you do not use mains gas, choose electricity only.
Example calculation
Using 225 kWh over 30 days with the October–December electricity examples:
- Usage: `225 × 26.32 / 100 = £59.22`.
- Standing charge: `30 × 54.83 / 100 = £16.449`.
- Electricity total: £75.67, rounded from £75.669.
With gas enabled at the prefilled 958 kWh, 7.97p/kWh and 29.68p/day, gas adds £85.26 (unrounded £85.2566). The combined result is £160.93, calculated from the unrounded fuel costs. Account credits, debt and other adjustments are excluded.
How to use the result
Use the result to sense-check a bill, budget a typical month, or compare how much of your bill is fixed standing charge rather than energy use. Supplier credits, debt repayment, discounts, missed meter readings, or estimated readings can make the real bill different.
Assumptions and limitations
The estimate covers usage and standing charges for the inputs entered. It is not a guaranteed annual bill, a switching recommendation or regulated energy advice.
Default rates and sources
Rate examples were checked on 14 October 2026 against Ofgem unit rates and standing charges for 1 October to 31 December 2026. They are Great Britain averages for Direct Debit, not Northern Ireland rates or a quote for every household. Regional, payment-method, meter and tariff differences matter; use your supplier's applicable rates.
Ofgem states that gas figures include 5% VAT, while electricity has no VAT from 1 October 2026 to 31 March 2027. Enter bill rates with any applicable VAT included: the calculator does not add VAT again. This VAT difference also means costs across the affected periods are not directly comparable. Bills crossing a rate-change date should be calculated separately for each part using its own usage, days and rates.
These examples expire after 31 December 2026; they are not a future tariff forecast. Annualised results assume the entered rates stay constant. Usage amounts and comparison offers are editable illustrations, not current official consumption benchmarks or live supplier offers.
Frequently asked questions
Does the price cap limit my total bill?
No. Ofgem explains that the price cap limits unit rates and standing charges for covered default tariffs, but your total bill still depends on how much energy you use.
Why do I pay when I use no energy?
The standing charge is a daily fixed charge for being connected to the network and related supply costs. It is charged even when usage is zero.
Should I use monthly or annual kWh?
Use the kWh for the same period as the number of days entered. The calculator will annualise the result for comparison.
Does this use my exact regional price cap?
No. The defaults are national average Direct Debit examples. Enter the rates from your bill or supplier notice for your exact estimate.
Can standing charges make a zero-usage bill non-zero?
Yes. Standing charges are daily fixed charges, so the calculator includes them even when usage is zero.