A kilowatt hour (kWh) is the amount of energy used by a 1,000-watt appliance running for one hour, and it is the unit your gas and electricity are billed in. In the UK, the average price-capped rate is 26.11p per kWh for electricity and 7.33p per kWh for gas, correct from 1 July to 30 September 2026.
In short: 1 kWh = a 1,000W appliance running for 1 hour. Electricity costs 26.11p per kWh plus a 57.19p daily standing charge. Gas costs 7.33p per kWh plus a 29.04p daily standing charge. A medium household uses about 2,500 kWh of electricity and 9,500 kWh of gas a year.
This guide explains what a kWh measures, what one costs, how many your home is likely to use, and what your appliances cost to run.
One kilowatt hour is the energy used by a 1,000-watt appliance running for one hour. It is a measure of quantity — how much energy you have consumed, which is why it is the unit that appears on your bill.
One kWh is roughly equal to:
Both gas and electricity are billed in kWh, even though a gas meter does not measure kWh directly. Gas meters record volume, cubic metres or cubic feet, and your supplier converts that volume into kWh on your bill so that both fuels can be priced on the same basis.
The table below shows the average price-capped rates for a household on a standard variable tariff paying by Direct Debit in England, Scotland and Wales.
| Fuel | Unit rate (per kWh) | Standing charge (per day) |
|---|---|---|
| Electricity | 26.11p | 57.19p |
| Gas | 7.33p | 29.04p |
Correct as of August 2026. These rates apply from 1 July to 30 September 2026 and include VAT at 5%.
They are averages, and rates vary by region. Ofgem sets 14 separate regional caps, one for each electricity distribution area. Your rate depends on where you live, because network costs differ across the country.
They vary by payment method too. Direct Debit is the cheapest of the capped payment methods. Prepayment sits slightly lower on the annual figure but works differently, and paying on receipt of a bill is the most expensive.
They are a ceiling, not a price. The cap sets the maximum a supplier can charge on a default tariff. Suppliers are free to charge less, and many do.
Fixed tariffs sit outside the cap entirely. A fixed rate can be above or below the capped level. Fixing when rates are expected to rise can save money; fixing before a fall costs you. Fixed tariffs are not automatically cheaper, and the only way to know is to compare what is actually available for your postcode.
Coming 1 October 2026: VAT on domestic electricity falls from 5% to 0% for the rest of the 2026/27 financial year, worth around £45 a year off a typical electricity bill. Gas stays at 5%.
On 21 July 2026, the government announced that VAT on domestic electricity would fall from 5% to 0% from 1 October 2026 for the remainder of the 2026/27 financial year. It is expected to take around £45 a year off a typical electricity bill.
The change applies to electricity only, gas remains at 5% VAT. The government has said it expects suppliers to pass the saving on to all customers, including those on fixed tariffs.
If you are reading this before October, the 26.11p figure above still applies. From 1 October, expect the electricity unit rate to fall by roughly 5% as the VAT comes off, before any separate change to the cap itself.
For a fuller breakdown, see our guide to energy prices per kWh, or run a comparison to see what suppliers are offering for your postcode.
The July 2026 cap has been widely reported as both £1,862 and £1,663 a year. Both numbers are real, and neither is wrong.
On 1 July 2026, Ofgem changed the assumed usage figures it uses to convert unit rates into an annual bill, because households are using less energy than they were. Under the old assumptions, the cap works out at £1,862. Under the new, lower assumptions, the same rates produce £1,663.
Nothing about the underlying unit rates or standing charges changed between those two figures, only the benchmark consumption used to calculate the illustrative annual bill. This is worth understanding, because a falling headline figure does not necessarily mean falling prices. The unit rates in the table above are the reliable comparison, which is another reason to think in pence per kWh rather than in annual totals.
A kW (kilowatt) is a rate of power, how fast an appliance draws energy. A kWh (kilowatt hour) is a quantity of energy, how much has actually been used over time.
The clearest way to think about it is speed and distance:
A 2kW heater draws energy at twice the rate of a 1kW heater. But run the 1kW heater for two hours, and the 2kW heater for one, and both have used exactly 2 kWh, and both cost the same.
Appliances are rated in kW or watts. You are billed in kWh. The rating tells you how much power the appliance needs to work; multiply that by how long you run it, and you get the number that appears on your bill.
The formula is simple:
Watts ÷ 1,000 × hours used = kWh
So a 1,500W dishwasher running for 40 minutes uses 1,500 ÷ 1,000 × 0.67 = 1 kWh.
Your kWh usage appears in the section showing how your charges were calculated, usually laid out as a line reading something like “2,340 kWh at 26.11p”. You will normally see:
Gas and electricity are shown as separate blocks, each with their own usage and rate.
An in-home display shows usage in kWh, usually with a running total for the day, week or month, and often a cost figure alongside it. It is the fastest way to see what a specific appliance costs: note the reading, run the appliance, and note it again.
The most reliable method, and the one that does not depend on your supplier’s estimates.
For electricity, subtract the earlier reading from the later one. The difference is your usage in kWh directly.
For gas, the calculation has an extra step because the meter measures volume:
If your gas meter is an older imperial one measuring in hundreds of cubic feet, multiply the difference by 2.83 first to convert to cubic metres, then follow the steps above.
Watch for the “E”. An “E” next to a reading on your bill means it is estimated, not measured. Submit an actual reading before your bill is issued and every figure on it becomes real.
If your bill says “E” next to a reading, it is estimated, your supplier has guessed based on past usage rather than reading your meter.
Estimates are frequently wrong, and they matter more than people expect. An overestimate means you are paying for energy you have not used and building a credit balance you could be keeping. An underestimate means a catch-up bill later, often at a worse moment. Any figure you calculate from estimated readings is guesswork built on guesswork.
Submit an actual reading before your bill is issued, or fit a smart meter, and the numbers become real.
Ofgem publishes benchmark figures for low, medium, and high-usage households, updated on 1 July 2026 to reflect the fact that homes are using less energy than they were.
| Usage level | Per year | Per day |
|---|---|---|
| Low | 1,600 kWh | 4.4 kWh |
| Medium | 2,500 kWh | 6.8 kWh |
| High | 3,800 kWh | 10.4 kWh |
| Usage level | Per year | Per day |
|---|---|---|
| Low | 6,000 kWh | 16.4 kWh |
| Medium | 9,500 kWh | 26.0 kWh |
| High | 14,000 kWh | 38.4 kWh |
| Usage level | Per year | Per day |
|---|---|---|
| Low | 1,900 kWh | 5.2 kWh |
| Medium | 3,400 kWh | 9.3 kWh |
| High | 6,100 kWh | 16.7 kWh |
Multi-rate households use more electricity overall because many of them heat with it rather than with gas. Ofgem assumes roughly 58% of that usage falls in peak hours and 42% off-peak.
The daily figures are annual averages, not typical days. Gas usage in particular is wildly seasonal, a January day might be four or five times a July day. If you divide your winter bill by 30 and panic, that is why.
Households are using measurably less than they used to. Ofgem’s medium benchmarks fell by 7% for electricity and 17% for gas in the July 2026 review, reflecting efficiency improvements, warmer weather and people cutting back in response to price rises.
The national picture is more mixed than that suggests. Government figures published in DUKES 2026 show UK domestic electricity consumption rose to 96.2 TWh in 2025, up 2.6% on 2024, but still 7.1% below 2019. Domestic gas demand was broadly flat, down 0.8% on the year and around 15% below its 2017–2021 average. Electricity use is edging back up as homes electrify heating and transport, while gas continues its longer-term decline.
For a fuller breakdown by household size and property type, see our guide to average gas and electricity usage.
Costs below are calculated at the current capped electricity rate of 26.11p per kWh. Actual wattages vary between models, so treat these as a guide rather than a precise figure for your appliance.
| Appliance | Typical power | Energy used | Cost at 26.11p/kWh |
|---|---|---|---|
| LED light bulb | 9W | 0.05 kWh (5 hours) | 1p |
| Laptop | 50W | 0.4 kWh (8 hours) | 10p |
| Pedestal fan | 50W | 0.4 kWh (8 hours) | 10p |
| Television (55” LED) | 100W | 0.4 kWh (4 hours) | 10p |
| Electric blanket | 100W | 0.1 kWh (1 hour) | 3p |
| Fridge-freezer | 150W | 0.7 kWh (per day) | 18p per day |
| Kettle | 3,000W | 0.12 kWh (per boil) | 3p |
| Dehumidifier | 300W | 2.4 kWh (8 hours) | 63p |
| Washing machine | 2,100W | 0.8 kWh (40°C cycle) | 21p |
| Dishwasher | 1,500W | 1.2 kWh (eco cycle) | 31p |
| Electric oven | 2,100W | 1.5 kWh (per hour) | 39p |
| Electric shower | 8,500W | 1.4 kWh (10 minutes) | 37p |
| Fan heater | 2,000W | 2 kWh (per hour) | 52p |
| Tumble dryer (vented) | 2,500W | 4.5 kWh (per cycle) | £1.17 |
| Electric car (full charge) | 7kW charger | 60 kWh (excluding charging losses) | £15.67 |
Heat is what costs money. Everything expensive on this list produces heat: the dryer, the shower, the oven, the heater. Electronics barely register by comparison. If you are looking for savings, that is where they are.
Duration matters as much as wattage. A kettle is one of the highest-wattage things in your home and costs about 3p to use, because it runs for two minutes. A dehumidifier draws a tenth of the power and costs twenty times as much, because it runs all evening.
Higher wattage does not always mean higher running cost. A powerful appliance that finishes quickly can use less energy than a weaker one grinding away for longer. A heat pump tumble dryer, for example, draws less power and uses roughly a third of the energy of a vented model per cycle.
EV charging changes the maths entirely. At the capped rate, a full charge costs over £15. On a dedicated EV tariff with cheap overnight rates, the same charge can cost a fraction of that. If you drive an electric car and are on a standard tariff, that is likely the single largest saving available to you.
Work out what your own appliances cost to run at current rates.
Use the electricity cost calculator
Your gas meter measures the volume of gas passing through it, not the energy content. Your bill shows kWh because energy, not volume, is what you are actually buying, and because the energy content of gas varies slightly depending on its composition.
The conversion works like this:
Cubic metres × 1.02264 × 39.5 ÷ 3.6 = kWh
Where 1.02264 is a volume correction factor and 39.5 is the calorific value in megajoules per cubic metre. The exact calorific value is printed on your bill and changes slightly from one period to the next.
If your meter is imperial and reads in hundreds of cubic feet, multiply your reading difference by 2.83 to get cubic metres before you start.
Our full guide on how to convert gas units to kWh works through the calculation step by step with examples for both meter types.
The unit rate is not fixed by law, and it is not the same for everyone. Four things change what you pay.
Your tariff. This is the big one and the one you control. A standard variable tariff tracks the price cap. A fixed tariff locks your rate for the length of the deal. Suppliers also offer time-of-use tariffs with much cheaper overnight rates, which are worth serious consideration if you have an EV, a heat pump or storage heaters.
Your supplier. Different suppliers charge different rates for identical energy. There is no quality difference in the electricity, it comes down the same wires whoever bills you.
Your payment method. Rates also vary by payment method. Direct Debit generally offers lower rates than paying on receipt of a bill, while the treatment of prepayment customers differs under the cap and should be compared separately. If you are paying quarterly by cheque or card, switching to Direct Debit will usually reduce your energy costs, although you should make sure the payment date and amount suit your household budget.
Your region. You cannot change this one. Network costs differ across the 14 distribution regions, and your rate reflects where you live.
If you have never switched, or your previous fixed deal has ended, you may now be on a standard variable tariff. That rate is the maximum permitted under the cap, but it is not necessarily the cheapest tariff available to you.
A comparison takes a few minutes and needs your postcode and a rough idea of your annual usage, which, if you have read this far, you now know how to find.
See what your unit rate could be instead.
Compare energy prices
The average price-capped rate is 26.11p per kWh for electricity on a standard variable tariff paid by Direct Debit, correct from 1 July to 30 September 2026. Rates vary by region and payment method, and fixed tariffs can be higher or lower than the capped rate.
A medium-usage UK household uses around 6.8 kWh of electricity and 26 kWh of gas per day, based on Ofgem’s benchmark annual figures of 2,500 kWh and 9,500 kWh. These are annual averages, actual daily gas usage is far higher in winter than in summer.
For electricity alone, yes, that is roughly three times the medium household benchmark of 6.8 kWh a day, and suggests electric heating, an EV, or a large property. For gas it is below average, as a medium household uses around 26 kWh a day across the year.
A kW measures power, the rate at which an appliance uses energy. A kWh measures energy consumed over time, which is what you are billed for. Think of kW as miles per hour and kWh as miles travelled. A 2kW appliance running for one hour uses 2 kWh.
Gas meters measure volume, but you are buying energy, and the energy content of gas varies slightly. Your supplier converts your volume reading into kWh using a calorific value printed on your bill. Billing both fuels in kWh also lets you compare gas and electricity prices directly.
No. Cost depends on wattage multiplied by time. A 3,000W kettle costs around 3p per boil because it runs for two minutes, while a 300W dehumidifier costs around 63p over an evening. An efficient appliance that finishes faster can cost less than a low-wattage one running for hours.
A kilowatt hour is the energy used by a 1,000-watt appliance running for one hour, and it is the unit both your gas and electricity are billed in. As of August 2026, the capped rates are 26.11p per kWh for electricity and 7.33p per kWh for gas.
How many kWh your household uses is only half of what you pay. The other half is the price you pay for each one, and unlike your usage, that is something you can change today. Compare energy prices for your postcode, or work out what your appliances are costing you with our electricity cost calculator.
Last updated: August 2026. Next review: October 2026, to reflect the removal of VAT on domestic electricity and the October–December price cap.
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