Energy Bill Calculator UK
Example rates: the Ofgem price-cap averages for Direct Debit, 1 October to 31 December 2026. Change them to the rates on your bill — your supplier’s rates may be lower if you are on a fixed deal.
Model: annual bill = (kWh × unit rate) + (standing charge × 365 days), for each fuel. Monthly Direct Debit is the annual figure divided by 12. The “typical household” comparison uses Ofgem’s £1,723 figure for October to December 2026.
The price cap is a cap on rates, not a cap on your bill
This is the single most misunderstood fact about UK energy bills, so it is worth saying plainly. The Ofgem price cap limits the unit rate (pence per kWh) and the daily standing charge a supplier can charge on a standard variable tariff in England, Scotland and Wales. It does not limit how much energy you can use, and it does not limit your total bill. A household that uses twice the typical amount of energy pays roughly twice the typical bill, even while the cap is in force. The £1,723 headline is what a household using exactly the typical amounts — 2,500 kWh of electricity and 9,500 kWh of gas a year, the figures Ofgem calls Typical Domestic Consumption Values — would pay at the capped rates.
The cap is reset every three months, in January, April, July and October, and each new level is announced about five weeks before it starts. For 1 October to 31 December 2026 the capped averages for Direct Debit customers are 26.32p per kWh for electricity with a 54.83p-a-day standing charge, and 7.97p per kWh for gas with a 29.68p-a-day standing charge. That is a 4% rise on the July to September 2026 cap of £1,663. The January to March 2027 cap was due to be announced by 25 November 2026. If you are reading this after that date, the rates in the calculator may be out of date — check Ofgem’s site and type in the new ones.
Where your bill actually goes
| Part of the bill | Typical household | Notes |
|---|---|---|
| Electricity used (2,500 kWh × 26.32p) | £658.00 | Depends entirely on how much you use |
| Electricity standing charge (54.83p × 365) | £200.13 | Charged every day, even if you use nothing |
| Gas used (9,500 kWh × 7.97p) | £757.15 | Mostly heating and hot water |
| Gas standing charge (29.68p × 365) | £108.33 | Charged every day, even if you use nothing |
| Total | £1,723.61 | Ofgem rounds this to £1,723 |
Two things stand out. First, standing charges are £308.46 a year — nearly 18% of the typical bill — before a single light is switched on. That is why small households, who use little energy, pay a disproportionately high price per kWh. Second, gas is the bigger cost for most homes, because heating a home takes far more energy than running its appliances. In a typical house, space heating is about half of all energy use. Turning the thermostat down by one degree typically cuts heating costs by around 10%, which on the figures above is roughly £75 a year.
How to find your real usage
Your annual kWh is printed on your bill, usually as “usage this year” or on a yearly summary. If you have a smart meter, your supplier’s app shows it too. If you have just moved in and have no history, the typical values are a starting point: a one-bedroom flat might use 1,800 kWh of electricity and 8,000 kWh of gas; a three-bedroom house more like 2,900 kWh of electricity and 12,000 kWh of gas; a large detached house 4,000 kWh and 14,000 kWh or more. But these are rough guides — an electric shower, an electric car, or an old boiler can move the numbers a lot. The most accurate estimate always comes from your own meter readings over a full year, because heating use is concentrated in winter and a summer reading tells you almost nothing about January.
Direct Debit: why your monthly payment is not your monthly use
Most households pay by monthly Direct Debit, and the monthly figure is the annual bill divided by 12 — £143.63 a month for the typical household. You pay the same in July as in January, even though you use far more energy in January. Your supplier estimates your annual use, sets the monthly payment, and reviews it once or twice a year. If the estimate is too low, you build up a debt; too high, and you build up a credit balance. Check the balance every few months and send a meter reading if you do not have a smart meter — an estimated bill is only ever a guess, and suppliers’ guesses are wrong in both directions.
What actually cuts the bill
- Turn the thermostat down 1°C. Roughly 10% off heating costs — about £75 a year for the typical household.
- Fix draughts. Draught-proofing strips around doors and windows are cheap and cut the heat escaping from a home.
- Use heating controls properly. A timer and a room thermostat stop the boiler heating an empty house.
- Shorter showers. Cutting a daily shower by two minutes saves gas and water — gas for heating the water is a large part of many bills.
- Check whether a fixed tariff beats the cap. The cap is the maximum on a standard variable tariff, not the cheapest price. Compare fixed deals, but check exit fees and the length of the fix before switching.
Electric or gas only? What changes
Not every home has both fuels. If your home is electric-only — a flat with electric heating and no gas supply — set the gas use to zero and the gas part of the bill disappears, but watch out: without gas, your electricity use will be much higher than 2,500 kWh, because electric heating uses a lot of power. A home heated with electric storage heaters can easily use 4,000 to 6,000 kWh of electricity a year. If you have an Economy 7 or other time-of-use tariff, you have two unit rates — a cheaper night rate and a dearer day rate — and this calculator’s single-rate model will not match your bill exactly. As a rough guide, put in the average of your two rates weighted by how much you use at each time, or work out the day and night parts separately and add them together.
Prepayment meter customers usually pay slightly more than Direct Debit customers for the same energy, because the capped rates for prepayment are higher. The calculator still works — just type in your prepayment rates from your bill or your meter’s display. And if you have solar panels, the electricity you generate and use yourself does not come through your meter at all, so your billed kWh will be lower than your actual use. The calculator works on billed kWh, which is the right number for estimating the bill.
Related: Electricity Cost Calculator · Appliance Running Cost Calculator · Take Home Pay Calculator
Sources: Ofgem, “Energy price cap” and price cap unit rates and standing charges, 1 October to 31 December 2026 (electricity 26.32p/kWh, standing charge 54.83p/day; gas 7.97p/kWh, standing charge 29.68p/day; typical dual-fuel household £1,723, based on 2,500 kWh electricity and 9,500 kWh gas). Checked 13 November 2026.