Hot Tub Running Cost Calculator
Estimate the daily, monthly and yearly cost to run your hot tub at 2026 UK electricity rates
Last updated: June 2026
Hot Tub Running Cost Calculator
Estimate how much your hot tub costs to run per day, week, month and year based on its insulation, your electricity unit rate and how often you use it.
Default is the Ofgem price cap rate of 24.67p/kWh (1 Apr-30 Jun 2026). Check your latest bill for your exact rate.How much does a hot tub cost to run in the UK?
A hot tub is a luxury that comes with an ongoing electricity bill, and for most UK owners the heater is by far the biggest cost. This free hot tub running cost calculator estimates your spa's daily, weekly, monthly and yearly electricity cost using your real unit rate, your tub's insulation quality and how often you keep it warm. It is designed for anyone thinking about buying a hot tub, comparing an inflatable versus a rigid model, or simply trying to understand a higher-than-expected energy bill.
As a rough guide, a typical well-used hot tub draws around 3-8 kWh per day depending on how well it is insulated, the outdoor temperature and your target water temperature. At the Ofgem price cap rate of 24.67p per kWh (1 April to 30 June 2026), that works out at roughly £0.74 to £1.97 per day for a tub kept warm all year. The calculator above lets you replace these averages with your own figures for a personalised estimate.
How the hot tub running cost calculator works
The calculator uses a simple, transparent formula:
- Daily cost = daily kWh × (unit rate ÷ 100)
- Monthly cost = daily cost × 30.42 (average days per month)
- Yearly cost = daily cost × 365
Daily kWh is taken from your chosen insulation preset (efficient 3 kWh, standard 5 kWh, or poorly insulated 8 kWh per day), then scaled by how often you keep the tub warm. If you pick a heat pump, the energy used is divided by its coefficient of performance (COP) — a COP of 4 means the heat pump moves about four units of heat for every unit of electricity, so it uses roughly a quarter of the power. The default unit rate is the Ofgem price cap electricity rate of 24.67p/kWh, but you should enter the exact rate from your own bill for the most accurate result.
Worked example
Suppose you own a standard, average-insulated hot tub (5 kWh/day) with a normal electric heater, kept warm all year, and you pay the Ofgem price cap rate of 24.67p/kWh:
- Daily cost = 5 kWh × £0.2467 = £1.23 per day
- Weekly cost = £1.23 × 7 = £8.63 per week
- Monthly cost = £1.23 × 30.42 = £37.52 per month
- Yearly cost = £1.23 × 365 = £450.23 per year
That is around 1,825 kWh per year. Fitting a better insulated cover could save roughly £90 a year (about 20%), and switching to a heat pump could cut the heating bill by hundreds of pounds annually.
Frequently asked questions
How much does it cost to run a hot tub per month in the UK?
For a standard, average-insulated hot tub kept warm all year at the Ofgem price cap rate of 24.67p/kWh, expect roughly £37 to £38 per month. A well-insulated tub may cost around £22-23/month, while an older or poorly insulated tub can exceed £60/month. Enter your own unit rate above for a precise figure.
Is it cheaper to leave a hot tub on or turn it off?
For regular users it is usually cheaper to keep the tub at a steady temperature, because reheating a fully cooled tub from cold uses a large burst of energy. If you only use it occasionally, lowering the temperature or switching it off between sessions can save money — use the "occasional / weekends only" option to compare.
Does a hot tub cover really reduce running costs?
Yes. Most heat is lost from the water surface, so a well-fitting, thick insulated cover is the single most cost-effective way to reduce running costs — often saving around 15-25% on the heating bill. Replacing a worn, waterlogged cover can pay for itself within a couple of seasons.
Are hot tub heat pumps worth it?
Heat pumps can be three to five times more efficient than a standard electric element, so they can dramatically cut yearly running costs — the calculator shows the saving for a COP 4 heat pump. The upfront cost is higher, so they make most sense for tubs that are heated heavily and used all year.
Source & methodology
Electricity unit rate is the Ofgem energy price cap for the period 1 April to 30 June 2026 (24.67p per kWh on a standard variable tariff paying by Direct Debit). Daily kWh ranges and heat-pump COP figures are based on Energy Saving Trust guidance and manufacturer specifications. Source: Ofgem — Changes to the energy price cap (1 April to 30 June 2026). Figures are estimates for guidance only; your actual cost depends on your tariff, weather, usage and tub condition.