How much does it cost to run a hot tub per month in the UK?
An inflatable hot tub held at temperature uses between 17.25 and 18.7 kilowatt hours a day on Lay-Z-Spa's published test data, so at the current Ofgem cap rate of 26.11p per kWh it costs £4.56 a day and £138.58 a month. Over a full year that is £1,663 for a tub left switched on.
Where the electricity goes
A hot tub has three loads and only one of them matters. The heater is rated around 2060 watts, the filter pump runs at a few hundred watts, and the massage blower is used in short bursts. Nearly all the money goes on the heater holding the water at temperature against the heat the tub loses to the air.
Lay-Z-Spa publishes its own test data rather than leaving buyers to guess, and the tests come out between 17.25 and 18.7 kilowatt hours of energy used per day. That is the figure this guide works from, taking 17.45 as the middle of the range.
Two things about that number. It is measured in mild conditions, so a frosty week will beat it, and it assumes the insulated lid is on when the tub is not in use. A tub sitting uncovered in a breeze loses heat far faster than any published test allows for.
It also explains why hot tub running costs quoted online vary so wildly. A retailer quoting a pound a day is describing a well insulated hard sided spa in summer with the lid on, and an owner quoting ten pounds a day is describing an inflatable tub in January with the cover half off. Both can be true, and neither is a safe number to budget from unless you know which one your own garden looks like.
The sum, worked in full
Take 17.45 kilowatt hours a day and multiply by the cap rate of 26.11 pence. That is £4.56 a day.
A week is £31.89. A month, taken as 30.4 days, is £138.58. A full year is £1,663. Those are running costs alone, with the daily standing charge left out because you pay it whether the tub is filled or drained.
Work it out for your own inflatable hot tub
Type in the wattage from the plate on the back, then your own unit rate. The numbers update as you type.
What it costs at each end of the tested range
| Daily energy use | Per day | Per week | Per month | Per year |
|---|---|---|---|---|
| 17.25 kWh, best case in the test range | £4.50 | £31.53 | £137.00 | £1,644 |
| 17.45 kWh, middle of the range | £4.56 | £31.89 | £138.58 | £1,663 |
| 18.70 kWh, worst case in the test range | £4.88 | £34.18 | £148.51 | £1,782 |
| Appliance | Typical draw | Usage we assume | Per hour (UK) | Per usage (UK) | Per month (UK) | Per hour (US) |
|---|---|---|---|---|---|---|
| Inflatable hot tub | 2060 W | per 24 hours holding temperature | 53.8p | £4.56 | £138 | 37.8 cents |
Rates: Ofgem cap 1 July to 30 September 2026 at 26.11p per kWh (source), EIA residential average June 2026 at 18.34 cents per kWh (source). Checked 2026-09-22.
In the United States the same tub costs $3.20 a day at the EIA residential average of 18.34 cents per kilowatt hour, which is $97.34 a month. In Texas at 15.94 cents it falls to $84.60 a month, and in California at 34.74 cents it climbs to $184.39, which is why hot tub running cost threads read so differently depending on the state the writer lives in.
Six things that actually cut the bill
- Keep the lid on and keep it dry. A waterlogged cover insulates badly, and the lid is doing more work than any other part of the tub.
- Put a thermal ground mat underneath. An inflatable tub sits straight on a cold patio and loses heat downwards all day.
- Drop the set temperature by one degree. Every degree is heat the tub has to replace continuously, and most people cannot tell thirty eight from thirty seven once they are in.
- Use a windbreak. Moving air strips heat off the cover and the sides far quicker than still air does.
- Run the filter pump on a schedule rather than continuously, within what the manual allows, because the pump is a small load that runs for a lot of hours.
- Do not drain and refill more often than the water chemistry needs. Every refill starts the heating from mains temperature, which is the single most expensive thing a hot tub does.
Leave it on, or switch it off between soaks
This is the argument every hot tub owner has, and it has a number attached. Holding temperature costs £4.56 a day. Heating a thousand litre tub from five degrees to thirty eight takes 38.4 kilowatt hours of heat, which is £10.02, and at around two kilowatts of heater it takes the best part of a day to get there.
So switching off for two days saves £9.12 and costs £10.02 to recover. You lose money and you lose the use of the tub while it climbs back. Switch it off for a fortnight and the sums flip, since you save £63.79 and still only pay £10.02 to reheat.
One thing worth checking before any of this is your tariff. A hot tub is a big enough load to justify moving to a time of use deal with cheap overnight units, because the heater can do most of its work while the rate is low and the tub does not care what time it heats.
The honest comparison for the rest of the house is stark. A hot tub at £138.58 a month costs more than an inflatable spa owner's whole previous electricity bill in many homes. It is more than running a two kilowatt oil filled radiator for eight hours every single day, which comes to £127.17 a month, and it is fifteen times the £9.01 a month a daily eight minute electric shower costs. None of that makes a hot tub a bad purchase, but it does mean it belongs in the budget as a bill rather than as an appliance.
Common questions
How much does it cost to run a hot tub per day?
£4.56 a day for an inflatable spa held at temperature, using the middle of Lay-Z-Spa's published test range of 17.25 to 18.7 kilowatt hours and the cap rate of 26.11p per kWh. The bottom of that range is £4.50 a day and the top is £4.88.
How much does it cost to run a hot tub in the winter?
More than the published figure, because the test is run in mild conditions and heat loss rises as the air gets colder. The sensible way to plan is to treat £4.56 a day as the floor, expect a cold snap to push it well above that, and use a good insulated lid rather than guessing at a number.
Is it cheaper to leave a hot tub on all the time?
Usually yes for short gaps. Holding temperature costs £4.56 a day, while reheating a thousand litre tub from five degrees to thirty eight takes 38.4 kilowatt hours, or £10.02. Two days switched off saves £9.12 and the reheat costs more than that, so only switch it off if you are leaving it for a week or more.
Do inflatable hot tubs use a lot of electricity?
Yes, more than anything else in a normal household. At 17.45 kilowatt hours a day a hot tub uses about as much electricity as twenty five fridge freezers, and the monthly cost is higher than most people's entire electricity bill before they bought it.