How many watts does an electric shower use?

By Tom Calder · Figures checked 4 November 2026 · Costs at 26.32p per kWh (Ofgem cap, 1 October to 31 December 2026)

In short

An electric shower is rated at 7kW to 10.5kW, by far the biggest load on this list. An eight-minute shower uses about 0.93 to 1.4 kWh, around 25p to 37p at 26.32p per kWh.

A kettle coming to the boil beside a microwave and slow cooker in a warmly lit kitchen on a rainy evening

The numbers

Running watts: 7,000W to 10,500W; Triton’s range at 240V: 7kW (T50i) to 10.5kW (T80si Extra). At 230V the same showers deliver less: 6.5kW and 9.6kW.
Amps at 230V (most): 41.9A; From the 240V rating: at 230V the same appliance draws a little less.
Energy for an 8-minute shower: 0.93 to 1.4 kWh; Rated power at 240V for 8 minutes, an example length: 7kW to 10.5kW. At 230V, Triton’s figures (6.5kW to 9.6kW) give 0.87 to 1.28 kWh.
Cost for an 8-minute shower: 25p to 37p
Cost per hour at full power: £1.84 to £2.76
On a 1kWh power station: Hard-wired on its own circuit, so it can’t run from a power station
On a 2kWh power station: Hard-wired on its own circuit, so it can’t run from a power station

Costs use 26.32p per kWh, the Ofgem price cap's average Direct Debit electricity unit rate for 1 October to 31 December 2026. Your own rate is on your bill; on a fixed or time-of-use tariff it will differ.

How it’s used, and what that costs

Triton lists its showers at 240V from 7kW (T50i) to 10.5kW (T80si Extra); at 230V they are 6.5kW and 9.6kW. The shower heats water as it passes through, so a higher rating can heat more water a minute.

So the cost is mostly down to how long you stand under it: every minute at 7kW to 10.5kW is 0.12 to 0.18 kWh.

The honest bit

An electric shower is hard-wired: Triton specifies a permanent connection through a double-pole isolating switch, on its own circuit (a 45A breaker for the 10.5kW model). Triton also requires a 30mA RCD on the shower circuit. Fitting or changing one is a job for a qualified electrician.

In a power cut: how long a power station would run it

Hard-wired on its own circuit, so it can’t run from a power station.

To size one for everything you’d want to keep running, use the sizer on our power stations comparison.

Common questions

How many amps does an electric shower draw?

Amps are watts divided by volts. Electric shower ratings are given at 240V; at the UK’s nominal 230 volts the same appliance draws a little less power, about 28 to 41.9 amps at full power. That is why each needs its own circuit: Triton specifies a 30A breaker for the 7kW T50i and a 45A one for the 10.5kW T80si Extra.

Home energy monitors →Power stations compared, with a sizer →Home backup power sizer →Running a fridge-freezer on a power station →How to lower your electricity bill →Electric heater safety and running costs →Every appliance’s running cost →

Compare: Immersion heater (3kW) · Kettle

Free

Free alerts for your home

Home Alerts emails you when a power cut, a Met Office warning or a flood warning covers your postcode. Free for your own home. Sign up in a minute.

Start free →

Sources (6)

Triton technical data via TLC Direct: T50i 7kW (240V) / 6.5kW (230V), 30A MCB; T80si Extra 10.5kW / 9.6kW, 45A MCB; permanently connected via a double-pole isolating switch
Ofgem: Energy price cap unit rates and standing charges, 1 October to 31 December 2026electricity 26.32p per kWh, Direct Debit; no VAT on electricity from 1 October 2026 to 31 March 2027
BLUETTI UK — Elite 200 V2 (runtime formula: DoD 90%, η 85%, self-consumption about 10W)
BLUETTI UK — Elite 100 V2 (self-consumption about 10W)
Jackery UK — runtime formula (capacity × 0.85 ÷ watts)
EcoFlow — test runtime before an emergency0.80–0.90 for AC; DC ports for routers and phones

PreparedBritain is independent and not affiliated with HM Government.