How much does it cost to run a hot tub?
Work out what any appliance costs to run per use, per month and per year on your own electricity rate — including what it draws on standby.
Using the German average of 38.69c/kWh — Eurostat, the second half of 2025.
The cost is dominated by keeping the water warm around the clock, not by the sessions you actually use it.
Common cases
What drives the cost
A hot tub's cost has very little to do with how often you use it. The overwhelming majority goes into holding several hundred litres of water at temperature around the clock, against a cold garden — the pump and jets during a session are a rounding error by comparison.
That makes insulation the whole game. A well-fitting, undamaged, thick cover is the single biggest factor, because most of the heat leaves through the surface. A waterlogged or warped cover can easily double the running cost, and it is the cheapest part of the tub to replace.
How this is worked out
Electricity is billed per kilowatt hour. An appliance's kilowatt hours are its power in kilowatts multiplied by the hours it runs — so a 2,000 W appliance running for 30 minutes uses 1 kWh. Multiply that by your unit rate and you have the cost. The standing charge is not included here because you pay it whether or not you switch anything on.
What this assumes
- The appliance draws its rated power for the whole time it is on. Anything thermostatically controlled — ovens, heaters, fridges — cycles on and off, so the real figure is lower.
- Your unit rate stays flat all day. On a time-of-use tariff the same appliance costs materially different amounts depending on when you run it.
- A year is 52 weeks of identical use, which overstates seasonal appliances and understates ones you use in bursts.
- The rate filled in for you is an average that spreads fixed charges across a year's usage, so it sits above what one extra unit really costs. Entering the unit rate from your own bill gives a closer answer.
Questions
Should I turn it off when I am not using it?
Usually not, if you use it weekly. Reheating a cold tub takes a great deal of energy and many hours, and often costs more than holding temperature would have. For a tub left unused for weeks, draining or dropping the temperature substantially does make sense.
Does lowering the temperature by a degree or two help?
Yes, more than you would expect. Heat loss scales with the difference between water and air temperature, so a couple of degrees lower is a proportionally larger saving in winter, when the gap and the cost are both at their greatest.
Does this include the standing charge?
No, and deliberately. The standing charge is a fixed daily fee for being connected at all, so it does not change when you run an appliance more or less. Including it would make every appliance look more expensive than it is.
Where do I find the wattage?
On the rating plate — usually a sticker on the back, base or inside the door — or in the manual. It is written as W or kW. If it only quotes amps, multiply amps by 230 to get watts.
Why is my bill higher than the total this gives?
Because this prices one appliance. Heating, hot water and the constant background draw of everything left plugged in usually make up more of a bill than the appliances people think to check.
Sources
- Ofgem — price cap unit rates — checked 2026-08-21
- Energy Saving Trust — quick tips to save energy — checked 2026-08-21
Rates from Eurostat for the second half of 2025. Last reviewed 3 September 2026.