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A hot tub uses between 3 and 7.5 kWh per day. What that costs depends on your electricity tariff: at 0.28 euro per kWh it works out at roughly 25 to 63 euro a month. The range is wide because it comes down to two things: how well the shell is insulated and whether the cover still closes properly.
I'll show you where that figure comes from, how to work it out for your own case rather than reading it off a table, and which changes actually bring it down. Heating is the dominant running cost, far larger than water and chemicals combined: that is where the money goes.
Where the consumption comes from: the heater and heat loss
A hot tub has two electrical loads and they matter very differently. The heater brings the water up to temperature and then holds it there, and across our whole range it is rated at 3,000 W. The pumps, for circulation and for the jets, draw far less and only while you are using them.
The part that surprises most people is that the cost does not depend on how often you bathe: it depends on how much heat the tub loses while you are not using it. The water sits at 37 °C around the clock, the air around it does not, and that difference is what the heater keeps compensating for. A tub used twice a week and one used daily consume almost the same.
Hence the practical consequence: the 3,000 W heater never runs continuously. It cycles, and the number of cycles depends on heat loss. One full hour of heater costs about 0.84 euro; at two hours a day you land near 50 euro a month, which is the real order of magnitude.
The calculation, with your own numbers
There is only one formula, and your bill has everything you need:
kWh per day × 30 × price per kWh = cost per month.
Take the price from your own bill, from the line showing the charge per kWh. As a reference point, the Italian energy regulator ARERA set a reference price of 27.97 euro cents per kWh including taxes for the first quarter of 2026, and that is the figure used below. Your own rate will differ by country, supplier and contract, so treat the table as a shape rather than as your bill.
At that price:
- 3 kWh a day: about 25 euro a month, 306 a year
- 4 kWh a day: about 34 euro a month, 408 a year
- 5 kWh a day: about 42 euro a month, 510 a year
- 6 kWh a day: about 50 euro a month, 613 a year
- 7.5 kWh a day: about 63 euro a month, 766 a year
Real consumption is measured, not estimated: a plug-in energy meter costing a few tens of euro, fitted between the tub and the socket, gives you the actual kWh over a week. It is the only way to know which row of that table you are really on, and it is worth doing before you switch supplier or start adding insulation.
Check the supply before you buy
This comes before consumption, because getting it wrong means the tub will not run at all.
The heater draws 3,000 W, or 3 kW. In Italy the standard domestic supply is rated at exactly 3 kW, so the heater alone takes all of it: nothing else in the house can be running, and an oven or a washing machine is enough to trip the breaker. Turn the jets on as well and the peak goes much higher: on a BL-832 hot tub the pumps alone come to nearly 6 kW.
So if you want to heat the water, the supply needs to be uprated to at least 4.5 kW. That is a change you request from your utility, with a connection fee and a slightly higher standing charge. Budget for it before buying, rather than discovering it after delivery. Standard domestic supply ratings vary by country, so check what yours is before assuming there is headroom.
There is one case where a 3 kW supply genuinely is enough: summer use without heating. From June to September the water reaches a usable temperature on its own, and if you do without the heater only the jet pumps remain, which stay under that threshold. It is a legitimate and common choice: the tub works as a cool or ambient-temperature pool, you use it in the warm months and close it down for winter. In that case the standard supply copes, and the figures in this guide should be read well below the range, because the dominant cost disappears.
The difference is clear cut: with the heater you use it all year at 37 °C and you need more power; without it you use it in summer at whatever temperature the weather gives you and you keep the supply you have. Decide which of the two you want before choosing a model, because that is what determines the installation.
The electrical connection guidance from our technical support sets out the requirements: the dedicated circuit, the residual current device and the cable cross-section are not optional, and an approved electrician should check them before delivery.
What moves the consumption, in order of weight
The thermal cover. This is the first factor and nothing else is close. An intact cover, properly seated, holds the heat already in the water; one left off, or with a crushed seal, loses it continuously. Before you look at your tariff, look at whether the cover closes and whether the foam core inside is still dry: once it soaks up water it gets heavy and stops insulating.
The set temperature. Every degree lower is less difference to compensate for. Going from 38 to 36 °C is a saving you notice on the bill and barely notice in the water.
Season and position. In January, with the tub exposed to wind, consumption can double compared with May. A tub sheltered by a wall or a hedge works less than one standing in the open.
Shell insulation. This is the one thing you cannot change afterwards, which is why it is worth looking at when buying: two tubs identical in size and jet count can consume very differently depending on how much insulation sits under the acrylic and around the equipment bay.
Is it worth switching it off between soaks?
Almost never, and it is the question I get most often.
Bringing 1,000 litres from ambient temperature up to 37 °C takes a lot of energy in one go, and the 3,000 W heater needs several hours to do it. Holding the temperature costs less than repeating that climb, as long as the gap between soaks is days rather than months.
The calculation only changes if the tub will sit unused for weeks: then lower the temperature rather than switching off entirely, which avoids both the standing consumption and the risk of freezing in the pipework. For a long winter shutdown the answer is different again, and it is the winter closure procedure described by our technical support: the tub is drained and the system made safe.
Where consumption sits in the full running cost
Electricity is not the only line, but it dominates. For a 700 to 1,000 litre tub in family use, orders of magnitude:
- Electricity: 300 to 760 euro a year, depending on insulation, season and set temperature
- Chemicals: 200 to 300 euro a year across sanitiser, algaecide and pH correctors
- Filter cartridge: one or two replacements a year
- Water: 12 to 18 euro a year, over 8 to 12 changes
The arithmetic says one thing: anyone worrying about the cost of the water is looking at the smallest line on the list. The detail of the other items, with filling and changing costs, is in the guide on what it costs to fill a hot tub and change the water.
Which tub uses less
Not the one with fewer jets, and not simply the smallest: the one that is better insulated and properly covered. That said, at equal insulation volume matters, because more water means more mass to hold at temperature.
If running cost is a criterion, compact models start ahead: the BL-862 hot tub measures 160 by 160 centimetres with 3 seats, the BL-881 160 by 200 with 4. A 7 seat tub like the BL-832, 200 by 250 centimetres, has more water to heat and sits at the top of the range.
The heater, on the other hand, is the same across the range, BL-837 included: 3,000 W. So it is not rated power that separates one model from another, but how long it has to stay on.
Frequently asked questions
How much electricity does a hot tub use?
Between 3 and 7.5 kWh a day, which at 0.28 euro per kWh is 25 to 63 euro a month. Where you land in that range depends on insulation, cover and season, not on how often you use it.
Is a 3 kW supply enough?
Only for summer use without the heater: then just the pumps run and a standard supply copes. If you want to heat the water, no: the heater draws 3,000 W and takes the whole supply on its own, so it needs uprating to at least 4.5 kW. Budget for that before buying, and check what the standard rating is where you live.
How much does it use in winter?
Up to twice as much as in spring, because the gap between 37 °C water and outside air is far larger. It is the season when the cover makes the biggest difference.
Should I switch it off between soaks?
No, if the gap is days: reheating 1,000 litres costs more than holding them. Lower the temperature instead, and for long winter shutdowns follow the winter closure procedure.
Do the jets use a lot?
Far less than the heater, and only while they are running. Jet count is not an indicator of consumption: a well-insulated tub with 92 jets can use less than a poorly insulated one with 20.
How do I find out what mine actually uses?
With a plug-in energy meter between the tub and the socket, left for a week. It gives you the real kWh, which is the only figure worth reasoning from.
What to do, in order
- First, decide whether you want to use it all year or only in summer: the first needs the heater and a supply of at least 4.5 kW, the second runs on a standard 3 kW supply.
- Measure real consumption with a plug-in energy meter for a week, before estimating anything.
- Multiply kWh per day by 30 and by the price per kWh on your bill: that is your true monthly cost.
- Check the cover: that it closes, that the seal is not crushed, that the foam core is not waterlogged. It is the highest-return fix there is.
- Drop the temperature by a couple of degrees and measure again after a week.
- Do not switch the tub off between soaks: if it will sit unused through winter, follow the winter closure procedure.
The most common mistake is hunting for savings in the electricity tariff before looking at the cover. Switching supplier moves a percentage; a cover that no longer closes can double the consumption, and it is fixed with a seal.
If you want a consumption comparison between two specific models, our customer service has the insulation data that does not appear on the spec sheets. Who we are and the experience behind this guide is on the about us page.
Source for the electricity price: ARERA, the Italian energy regulator, reference price for the first quarter of 2026 (typical customer, 2,000 kWh a year).
Catalogue figures in this guide (dimensions, jets, seats and heater rating) are read from the product pages and update with the catalogue: what you see is the current value. Consumption figures are orders of magnitude for a 700 to 1,000 litre tub in family use: real consumption depends on insulation, cover, set temperature, season and exposure, and has to be measured on site. Electricity prices and standard domestic supply ratings vary by country, supplier and contract: use the figures on your own bill, not the ones on this page.
