Energy Bill Calculator UK: Gas and Electricity
Estimate gas and electricity costs using your annual consumption and October–December 2026 reference rates. Replace the defaults with your own bill or tariff quote for a more useful comparison.
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A common mistake is focusing only on unit rates while ignoring standing charges, which cost about £308 a year for both connected fuels at the default rates. Smart meter data gives accurate usage figures, but many households still rely on estimates that can lead to shock bills.
Estimating your energy bill based on actual or expected usage helps you budget accurately and compare tariffs fairly. Enter your consumption details below to see projected annual costs.
Default rates reflect Ofgem's price cap for 1 October–31 December 2026 (GB average, Direct Debit). Checked: 12 October 2026. Annual figures hold these rates for 365 days, rather than predicting future caps.
What would gas and electricity cost at typical usage?
At the current medium benchmarks of 2,500 kWh electricity and 9,500 kWh gas, the default rates give £1,723.61 over 365 days, or £143.63 per month. This is an annualised example, not a forecast, a maximum bill or your supplier's Direct Debit.
Your Energy Usage
Uncheck for electricity only. A connected gas supply still has standing charges when usage is zero.
Ofgem GB single-rate benchmarks, effective 1 July 2026. Use your actual annual kWh where available; these are not bedroom-based predictions.
Choosing a fixed tariff does not load a quote. Enter the actual rates from your bill or offer.
Default rates: 1 October–31 December 2026. Ofgem GB averages for Direct Debit and single-rate electricity: electricity 26.32p/kWh + 54.83p/day; gas 7.97p/kWh + 29.68p/day.
These published prices already include applicable tax. Use the tax-inclusive rates from your own bill or quote for your region, payment method and tariff. Northern Ireland and multi-rate tariffs need their own rates.
Annual figures hold the entered rates for 365 days. They are an illustration, not a forecast of future quarterly caps or your Direct Debit payment. Fixed-deal figures are illustrative until you enter an actual quote.
Ofgem source · Checked 12 October 2026
Annualised cost at these rates
Estimated Annual Cost
£1,723.61
Monthly Equivalent
£143.63
Annual usage at unchanged entered rates for 365 days. Monthly figures divide by 12; seasonal bills and future rates can differ.
Cost Breakdown
£858.13
50% of total
£865.48
50% of total
Detailed Annual Costs
Electric bill calculator: electricity-only costs
If you have no mains gas — an all-electric flat, electric heating or a heat pump — use this electric bill calculator as an electricity-only tool: uncheck “I have a mains gas supply” and the results show electricity unit costs plus the electricity standing charge on its own. At the Ofgem capped GB average of 26.32p per kWh and 54.83p per day standing charge, the standing charge alone is £200 a year. Usage references below are not predictions for electrically heated homes; enter your actual annual kWh.
| Example | Electricity (kWh/yr) | Unit cost | Standing charge | Annual total | Per month |
|---|---|---|---|---|---|
| Low reference usage | 1,600 | £421 | £200 | £621 | £52 |
| Medium reference usage | 2,500 | £658 | £200 | £858 | £72 |
| High reference usage | 3,800 | £1,000 | £200 | £1,200 | £100 |
| Illustrative higher use | 5,400 | £1,421 | £200 | £1,621 | £135 |
Based on Ofgem's price cap unit rate and standing charge for 1 October–31 December 2026 (GB average, Direct Debit), held for 365 days; figures rounded to whole pounds. Economy 7 and other time-of-use tariffs need separate calculations for each rate.
What this means for your energy spend
At the entered rates, unit charges rise with consumption while standing charges apply for each connected supply. The price cap limits eligible tariff rates; it does not set a maximum household bill.
Worked example — electricity only. Using 2,500 kWh at 26.32p/kWh costs £658.00 in units plus £200.13 in standing charges:£858.13 over 365 days, or £71.51 per month. Additional EV charging costs depend on extra kWh, the tariff and vehicle efficiency.
Compare the whole bill at your actual consumption, including fees payable when switching. A fixed deal holds its contracted rates; future variable caps are unknown. Reducing consumption lowers unit costs but does not remove standing charges for a connected supply.
How to estimate your gas and electricity bill
Use a full year's consumption in kWh from actual readings, smart-meter records or your supplier's annual statement. A winter month multiplied by twelve can overstate demand; a summer month can understate heating use. Electricity used for an EV, electric heating or a heat pump belongs in the electricity total.
For each fuel: annual kWh × unit rate ÷ 100 + daily standing charge × 365 ÷ 100.
Rates are entered in pence. A £0.2632/kWh rate is 26.32p/kWh, not 0.2632p. Gas meters can record cubic metres or cubic feet: use the supplier's converted kWh consumption, not the raw meter reading.
The tool holds the entered rates unchanged for 365 days and divides the result by 12. It does not predict future quarterly caps, seasonal consumption or the Direct Debit your supplier will set. Contract fees, export payments, debt, credit balances and support adjustments are excluded.
Low, medium and high usage: worked bill examples
These are Ofgem's GB single-rate electricity and gas benchmarks effective 1 July 2026. They are reference points when actual consumption is unknown, not a prediction from bedroom count or a model of an all-electric heating household.
| Usage preset | Electricity kWh | Gas kWh | Annual cost | Monthly equivalent |
|---|---|---|---|---|
| low | 1,600 | 6,000 | £1,207.78 | £100.65 |
| medium | 2,500 | 9,500 | £1,723.61 | £143.63 |
| high | 3,800 | 14,000 | £2,424.42 | £202.04 |
The medium example includes £658.00 of electricity units, £757.15 of gas units and £308.46 of standing charges. Minor differences from a rounded headline cap can arise when calculating from published rounded average rates. Your actual regional tariff and usage remain the better inputs.
The former medium references were 2,700 kWh electricity and 11,500 kWh gas. A lower new benchmark changes this example's consumption, not your household's actual meter usage. Keep entering your real usage when comparing bills across periods.
Check the tariff, payment method and supply
The reference rates are GB averages for Direct Debit and single-rate electricity. They differ by region, supplier and payment method. A Northern Ireland tariff needs its own supplier rates. A fixed deal uses the rates in its actual offer; selecting a tariff label here does not load a quote.
For Economy 7 or time-of-use plans, multiply each rate by the kWh charged at that rate, then add the standing charge once. A single-rate annual calculation does not reproduce separate peak/off-peak, EV charging windows or export credits.
A connected gas supply still incurs standing charges at zero gas use. For no gas connection, turn off the mains-gas option; the calculation then excludes both gas units and standing charges. Reducing consumption lowers unit costs but does not remove daily charges for a connected supply.
Compare tariffs at the same annual consumption and include any applicable switching fee separately. Use the fixed-versus-variable comparison and standing-charge calculator for those next steps. The price cap is a limit on eligible rates, not a maximum bill.
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