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.
Inputs
Results
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
If a 30-day electricity bill shows 225 kWh, a 24.67p/kWh unit rate, and a 57.21p daily standing charge, the electricity estimate is about GBP 72.69 before any account balance adjustments.
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 default rates use Ofgem average Great Britain Direct Debit price-cap values for 1 April to 30 June 2026. Actual rates vary by region, payment method, supplier, meter type, and tariff. This is an estimate, not switching or regulated energy advice.
FAQs
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.
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Frequently asked questions
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.