Advanced options
A traditional electric sauna runs ~30-45 min heat-up at full power then cycles on the thermostat: budget ~1.5 hrs of element time per session at 75% duty. Infrared cabins heat YOU not the air: no warm-up, a third of the power, but a different experience (60C radiant vs 85C+ air). The gym membership comparison is the real decision: 3+ sessions a week at home beats most spa day-rates within a year: 1 session a week doesn't.
What The Sauna Cost Calculator Works Out
- Per session: heater kilowatts x 1.5 hours of element time x 75% duty cycle, multiplied by your electricity rate, which defaults to the current Ofgem price cap unit rate. A standard 6 kW heater spends 30 to 45 minutes at full draw reaching temperature then cycles on its thermostat, so a heat-up plus an hour's use burns 6 kWh to 7 kWh, about GBP 1.80 at current prices.
- Per year: the session cost multiplied by sessions a week and 52 weeks. Three sessions a week run under GBP 300 a year, less than a mid-tier gym membership, with the number of GBP 35 spa visits that would buy.
- The honest comparison: the sauna itself costs GBP 1,500 to GBP 6,000 installed, so the hardware spread over five years of your sessions dwarfs the electricity. The habit, not the kilowatt-hours, decides whether it is a bargain or garden furniture.
- Element time and duty cycle (advanced): edit the 1.5 hour and 75% defaults for your stove and routine. A well-insulated cabin cycles nearer 50% to 60%; an infrared cabin runs at close to 100% but skips the warm-up and needs about a third of the power.
- People per session (advanced): the sauna costs the same whether one or four people use it, so the per-person card divides the all-in cost by occupants. This is where the home sauna beats the spa fastest.
- Purchase cost and years (advanced): your actual quote, including the dedicated circuit a 6 kW to 9 kW heater needs, spread over however many years you expect to use it. Barrel saunas and garden pods run GBP 1,500 to GBP 4,000, quality indoor cabins GBP 2,000 to GBP 6,000.
- All-in per session and per year (advanced): electricity plus the amortised hardware, the true cost of each visit and the yearly total against the same visits bought at the spa.
- Sessions a week to beat the spa (advanced): how often you need to use the sauna for its all-in per-person cost to drop below your spa or gym visit price. Three months of paying for the commercial version first is the honest pre-purchase test.
- Electricity per month (advanced): the monthly kWh and cost that will show on the bill. Time heat-up by app or plug timer so it is ready when wanted rather than heated speculatively, and off-peak tariffs suit evening sessions naturally.