Short answer: at the Ofgem price cap for 1 October to 31 December 2026 (26.32p per kWh, paying by direct debit), a typical session costs about:
- £1.40–£3.00 in an electric barrel or cabin sauna;
- about 50p in a 2 kW infrared sauna.
A cold plunge chiller typically costs about £25–£50 a month. All these figures are estimates, so work out your own with the formula below.
The formula
Cost of a session = heater power (kW) × hours running × your unit rate (£ per kWh)
A heater draws full power while it heats up. Once the sauna reaches temperature, the thermostat switches it on and off to hold it there. In the examples below we assume it's on about half the time once hot. Glass fronts, cold or windy weather and a door left open push that up. Good insulation and a sheltered spot bring it down.
Your unit rate is on your electricity bill. The government has removed VAT from electricity bills from 1 October 2026 to 31 March 2027, and the rate below reflects that.
Worked examples
At 26.32p per kWh, with a 60-minute session:
| Sauna | Heater | Heat-up | Energy used | Cost per session |
|---|---|---|---|---|
| Small traditional, 2 person | 4.5 kW | 40 min | 5.25 kWh | £1.38 |
| Typical barrel, 4 person | 6 kW | 45 min | 7.5 kWh | £1.97 |
| Large cabin or panoramic | 9 kW | 45 min | 11.25 kWh | £2.96 |
| Infrared cabin (45-min session) | 2 kW | 15 min | 2.0 kWh | £0.53 |
Twice a week in the typical 6 kW barrel sauna comes to about £17 a month, or about £205 a year.
Wood-fired saunas
A wood-fired sauna uses no electricity to heat. Your cost is fuel, which depends on local log prices and how long you heat. Burn only dry, seasoned or kiln-dried wood, or the fuel the stove maker specifies. In a smoke control area, use authorised fuels or an exempt appliance.
Cold plunge chillers
A chiller works like a fridge: it runs hard to pull the water down, then cycles to hold the temperature. As an illustration, a chiller drawing 0.8 kW that runs 4–8 hours a day uses 3.2–6.4 kWh:
| Use | Energy per day | Cost per day | Cost per 30 days |
|---|---|---|---|
| Lower (mild weather, lid on, insulated tub) | 3.2 kWh | £0.84 | £25.27 |
| Higher (warm weather, colder target, lid often off) | 6.4 kWh | £1.68 | £50.53 |
What pushes it up:
- warm weather;
- a lower target temperature;
- a poorly insulated tub;
- leaving the lid off.
What brings it down:
- a good insulated lid;
- shade;
- sensible temperatures.
The chiller's power rating is on the product page. Our chiller guide explains the rest of the specification.
Using ice instead? Cooling a 300-litre tub from 12°C tap water to 3°C takes roughly 30–35 kg of ice each time. The water warms again within hours, so a chiller is usually the practical choice for regular use.
Five ways to cut running costs
- Insulate and shelter: a spot out of the wind, and a door that seals well.
- Match the heater to the cabin: an oversized heater cycles more; an undersized one never quite gets there.
- Use the timer: heat up so it's ready as you arrive, not an hour before.
- Keep the plunge lid on whenever the tub isn't in use.
- Check your tariff: some off-peak or time-of-use tariffs are cheaper at set hours.
FAQs
Is an infrared sauna cheaper to run?
Usually, yes. Infrared cabins use smaller heaters, often 1.5–3 kW, and heat up in 10–20 minutes. That's why a session costs pence rather than pounds. The experience is different, with lower air temperatures and no steam.
Does the standing charge change?
No. The daily standing charge (54.83p a day by direct debit from 1 October 2026) is paid whether or not you use the sauna, so we leave it out of per-session costs.
Will these costs change?
Yes. The price cap is reviewed every quarter, so the next one starts on 1 January 2027, and VAT on electricity returns from 1 April 2027 unless the government extends the cut. We update this guide when the cap changes.
Figures are estimates for guidance, using the Ofgem price cap average for England, Scotland and Wales. Your costs depend on your tariff, region, model, weather and how you use it.
Sources
- Ofgem, price cap from 1 October to 31 December 2026: https://www.ofgem.gov.uk/news/changes-energy-price-cap-between-1-october-and-31-december-2026
- UK Government, smoke control areas: https://www.gov.uk/smoke-control-area-rules