An electric shower rated 7–10.5 kW costs 3.1p to 4.6p a minute at 26.32p per kWh. An eight-minute shower costs 24.6p to 36.8p. With one eight-minute shower a day, that's roughly £7.47 to £11.21 a month in electricity.
Unlike most appliances, an electric shower runs at its full rating the whole time it's on, so the sums are simple. Time spent in the shower is the thing that matters most.
How powerful are electric showers?
Energy Savers and National Energy Action both give electric showers a rating of 7,000–10,500 W Typical (published). Triton's current UK range runs from 7.5 kW to 10.5 kW. A few models go higher: Kohler Mira's data sheet lists the Mira Sport Max at 10.8 kW on a 240 V supply, which falls to 9.9 kW on 230 V. Supply voltage changes the real draw a little, so treat the rating as a close guide.
The Centre for Sustainable Energy uses 9,000 W as a typical electric shower. At 26p per kWh, it puts the cost at £2.34 an hour, or 39p for 10 minutes.
Cost per minute, per shower and per month
| Rating | Per minute | 5 minutes | 8 minutes | 10 minutes | Per month (8 mins a day) |
|---|---|---|---|---|---|
| 7 kW | 3.1p | 15.4p | 24.6p | 30.7p | £7.47 |
| 8.5 kW | 3.7p | 18.6p | 29.8p | 37.3p | £9.07 |
| 9 kW | 3.9p | 19.7p | 31.6p | 39.5p | £9.61 |
| 9.5 kW | 4.2p | 20.8p | 33.3p | 41.7p | £10.14 |
| 10.5 kW | 4.6p | 23.0p | 36.8p | 46.1p | £11.21 |
| 10.8 kW | 4.7p | 23.7p | 37.9p | 47.4p | £11.53 |
The Energy Saving Trust says keeping showers to four minutes could save around £45 a year in GB, and a water-efficient shower head around £25 a year. Those savings depend on how long your showers are now and how your water is heated.
Electric shower vs mixer shower: a careful comparison
This is where it gets tricky, and you'll see confident claims both ways. An electric shower heats cold mains water as it flows, so its power limits how much hot water it can deliver. A mixer shower takes hot water from a boiler or cylinder, which usually allows a stronger flow. The two aren't like-for-like.
Here's an illustration using basic physics. It takes about 0.0349 kWh to warm one litre of water by 30°C, for example from 10°C to 40°C. These assumptions are ours, not measurements:
- Electric shower, 9 kW: it can deliver about 4.3 litres a minute at a 30°C rise. It costs 3.9p a minute.
- Mixer from a gas boiler, 8 litres a minute, assuming the boiler is 90% efficient: about 0.28 kWh of heat a minute, or about 2.5p a minute at the 7.97p gas cap rate.
- Mixer from an electric immersion-heated cylinder, 8 litres a minute: about 7.3p a minute at 26.32p, before any heat lost from the cylinder and pipes.
On these assumptions, a gas-heated mixer costs less a minute than a 9 kW electric shower, even though it uses nearly twice as much hot water. A mixer heated by an immersion heater costs more. Your boiler's efficiency, pipe runs, flow rate and cold water temperature will all change the answer. Water and sewerage charges, if you're metered, are extra in every case.
Worked examples
1. Cutting two minutes
Going from ten to eight minutes in a 9 kW shower saves 7.9p a shower. For one person showering daily, that's about £28.82 a year.
2. A household of four
Four people each taking an eight-minute shower a day in a 9.5 kW shower would use 4 × 8 × 4.2p = £1.33 a day, or about £40.56 a month.
3. A higher-powered replacement
Swapping an 8.5 kW shower for a 10.5 kW one costs 0.88p more a minute. A higher-powered shower can give a stronger flow at the same temperature, and some people shower for less time as a result. If the time stays the same, an eight-minute daily shower costs about £25.62 more a year. Any upgrade needs a suitable cable and circuit, so get an electrician's advice.
How we worked this out
Per minute = kW ÷ 60 × 26.32p. An electric shower draws its full rating while running, so we don't apply a cycling factor. Per month = one shower a day × 365 ÷ 12.
Mixer comparison: heat needed = litres × 4.186 kJ per kg per °C × temperature rise ÷ 3,600. The 30°C rise, 8 litres a minute flow and 90% boiler efficiency are our illustrative assumptions, not published figures for any shower. The gas rate is the Ofgem cap (7.97p/kWh). Heat losses from pipes and cylinders aren't included.
The EST savings figures are its own estimates. We haven't measured any shower.
Frequently asked questions
How much does a 10-minute electric shower cost?
At 26.32p per kWh, about 30.7p for a 7 kW shower, 39.5p for 9 kW and 46.1p for 10.5 kW.
How much does an electric shower cost per hour?
£1.84 to £2.76 an hour for 7–10.5 kW. An electric shower draws its full rating all the time it's on.
Is an electric shower cheaper than using the boiler?
It depends on how your water is heated and how much hot water you use. On our illustrative assumptions, a gas-heated mixer costs less a minute than a 9 kW electric shower, while a mixer heated by an immersion heater costs more.
Does a higher kW electric shower cost more?
Per minute, yes. A higher rating gives a stronger or hotter flow, so the total depends on how long you shower.
Does the standing charge change if I use an electric shower?
No. The 54.83p a day standing charge is the same however much electricity you use.
Sources
All checked on 29 October 2026. Figures are restated in our own words; follow the links for the originals.
- Energy Savers (Centre for Sustainable Energy) – How much electricity am I using?: https://www.energysavers.org.uk/advice/electricity-usage/
- National Energy Action – Electricity: what it costs to run appliances (A5 leaflet, April 2025 prices, PDF): https://www.nea.org.uk/wp-content/uploads/2025/06/Electricity-_A5-June-2025.pdf
- Centre for Sustainable Energy – How much electricity am I using? (26p/kWh, July 2026): https://www.cse.org.uk/advice/how-much-electricity-am-i-using/
- Triton Showers – Electric showers range: https://www.tritonshowers.co.uk/showers-taps/electric-showers
- Kohler Mira – Mira Sport Max with Airboost data sheet (PDF): https://techcomm.kohler.com/techcomm/pdf/1580485-W4-A_Sport%20V6.5%20Max.pdf
- Energy Saving Trust – Top tips to save energy and money in the bathroom (updated 6 Oct 2026): https://energysavingtrust.org.uk/top-tips-to-save-energy-and-money-in-the-bathroom/
- Ofgem – Energy price cap unit rates and standing charges: https://www.ofgem.gov.uk/your-energy-supply/your-energy-bill/energy-price-cap-unit-rates-and-standing-charges