Running a hot tub costs most owners about $20 to $50 per month in electricity — roughly $240 to $600 a year with another $20 to $40 a month for chemicals, water, and filters. A typical home spa draws 100 to 300 kWh of electricity each month, and at the 2026 U.S. average residential rate of about 18 cents per kWh, that lands most households in the $20–$50 range. Your exact bill depends on your local electricity rate, the size and insulation of your tub, the water temperature you keep, and how cold your climate gets.
Key Takeaways (TL;DR)
- Typical monthly electricity: $20–$60 (about $30–$50 for a well-insulated modern spa).
- All-in monthly running cost: roughly $40–$110 once you add chemicals, water, and filter replacement.
- Energy use: 100–300 kWh per month, depending on size, insulation, and weather.
- Biggest cost drivers: your electricity rate, your climate, the temperature setting, and the quality of your cover and insulation.
- Easiest savings: a tight, well-insulated cover plus a thermal blanket can cut heat loss by up to 70–75%.
How much does it cost to run a hot tub per month?
For most U.S. owners, a hot tub costs $20 to $50 per month in electricity alone, according to cost data compiled by Angi and HomeGuide. That works out to about $240 to $600 per year just to keep the water hot and the pumps running.
Add the other consumables like sanitizer and balancing chemicals, periodic water changes, and replacement filters — and the realistic all-in cost to run a hot tub averages around $500 a year, ranging from roughly $300 for a small, efficient, lightly used spa up to $1,100 or more for a large tub in a cold climate.
Here is the quick monthly math that answer engines and budgeters both want:
- Electricity: $20–$50/month
- Chemicals: $15–$40/month
- Water (drain & refill every 3–4 months): $5–$15/month amortized
- Filters (replaced every 1–2 years): $2–$10/month amortized
That puts the typical total monthly running cost between about $50 and $110, with electricity as the single largest line item.
What makes up your monthly hot tub cost?
Running cost is more than just the power bill. Here is how the four main expenses break down for a typical residential spa.
| Expense | Typical cost | How often | Notes |
|---|---|---|---|
| Electricity | $20–$60/mo | Ongoing | Largest cost; driven by heating and filtration |
| Chemicals | $20–$50/mo | Ongoing | Sanitizer, pH/alkalinity balancers, shock |
| Water | $20–$40 per change | Every 3–4 months | Depends on tub volume and local water rates |
| Filters | $20–$120 | Every 1–2 years | Clean regularly to extend life and save energy |
Electricity is the cost most people focus on because it is the one that scales with weather and habits. The rest are relatively predictable. For the full purchase-to-year-five picture including the spa itself, delivery, and electrical hookup — see our companion guide, Understanding Hot Tub Costs: What You’ll Really Pay From Purchase to Year Five.
How much electricity does a hot tub use?
A typical hot tub uses 100 to 300 kWh of electricity per month, or roughly 3 to 7.5 kWh per day. Most of that energy goes to heating the water and keeping it at temperature; a smaller share runs the filtration and jet pumps.
Energy use scales with the size (water volume) of the tub:
| Hot tub size | Monthly electricity use | Est. monthly cost @ 18¢/kWh |
|---|---|---|
| 2–3 person (compact) | ~90–120 kWh | ~$16–$22 |
| 4–5 person (medium) | ~120–150 kWh | ~$22–$27 |
| 6–7 person (large) | ~150–180 kWh | ~$27–$32 |
| Large/older or poorly insulated | 200–300+ kWh | $36–$54+ |
These are steady-state figures for a tub that is covered and kept at temperature. A brand-new, well-insulated spa in a mild climate can land at the bottom of these ranges, while an older tub with a waterlogged cover in a freezing climate can easily double them. Newer technology helps, too — spas built around energy-efficient heat pumps can use dramatically less electricity than traditional resistance heaters.
How your electricity rate changes the math
The single biggest variable in your bill is your local electricity price. The U.S. average residential rate is about 17.7 to 18.8 cents per kWh in 2026, according to the U.S. Energy Information Administration — but it ranges from under 12 cents in states like North Dakota to over 40 cents in Hawaii, per Choose Energy.
For a tub using a typical 150 kWh per month, here is how the rate changes your cost:
| Your electricity rate | Monthly cost (150 kWh) | Annual cost |
|---|---|---|
| 12¢/kWh (low) | $18 | $216 |
| 18¢/kWh (U.S. average) | $27 | $324 |
| 25¢/kWh (high) | $38 | $456 |
| 40¢/kWh (Hawaii-level) | $60 | $720 |
The formula is simple: monthly kWh × your rate per kWh = your monthly electricity cost. Find the “price per kWh” line on your utility statement, and you can replace every estimate above with your real number.
Does a 120V or 240V hot tub cost more to run?
This is one of the most common and most misunderstood questions about hot tub running costs. The short answer: over a full month, a 120V and a 240V hot tub of the same size and insulation use roughly the same total energy to hold a given temperature.
Here is why. A plug-and-play hot tub on a 120V circuit typically has a 1,500-watt heater, while a hardwired 240V spa usually has a 4,000-6,000-watt heater. The 240V heater is four times more powerful, so it reaches temperature faster but because a thermostat cycles the heater on and off to replace only the heat that is lost, both tubs ultimately consume the watt-hours needed to offset that heat loss. The 120V heater simply runs for longer stretches to do the same job.
The practical differences:
- 120V (plug-and-play): Often slightly cheaper to run because these tubs tend to be smaller and can’t heat and run high-speed jets at the same time but they recover heat slowly and can struggle in very cold weather.
- 240V (hardwired): Can be more efficient in cold climates because the powerful heater keeps up with heat loss instead of falling behind, and these spas usually have better insulation.
If you’re weighing the two, our full comparison breaks down the trade-offs: Plug-and-Play vs 240V Hot Tubs: Which Should You Buy?
What factors raise or lower your monthly cost?
Two identical-looking hot tubs can have wildly different running costs. These are the factors that matter most:
- Climate and season: In winter, the heater works harder to fight the temperature gap between the water and the outside air. Expect noticeably higher bills from late fall through early spring.
- Insulation quality: Full-foam and multi-layer insulated cabinets hold heat far better than budget tubs with minimal insulation.
- Cover condition: A cracked or waterlogged cover is the number-one hidden energy drain. A tight, well-fitting cover can prevent up to 70–75% of heat loss.
- Temperature setting: Every degree adds load. Dropping from 104°F to 100°F produces a noticeable savings.
- Usage habits: Frequent long soaks, open-cover lounging, and running high-speed jets all add kWh.
- Pump type: Variable-speed circulation pumps sip power compared with single-speed pumps running at full tilt.
- Water care: A clogged filter forces the pump to work harder and use more energy, so regular cleaning pays off.
9 proven ways to cut your hot tub running costs
You can typically shave 20–40% off your heating costs with a handful of low-effort changes:
- Upgrade or replace your cover. A tight, properly insulated cover is the single most effective fix. Replace any cover that is cracked, sagging, or waterlogged. (The Cover Guy)
- Add a floating thermal blanket. A blanket under the main cover cuts evaporative heat loss — the biggest source of loss by as much as 95%.
- Lower the temperature a few degrees. Moving from 104°F to 100°F when you’re not using the tub reduces standby heat loss with little comfort difference.
- Build a windbreak. Fences, panels, or shrubs that block wind can save an estimated 10–15% on heating, especially in exposed yards.
- Use off-peak heating. If your utility offers time-of-use rates, set a timer to heat at night when power is cheaper.
- Keep filters clean. Rinse filters regularly and replace them on schedule so the pump doesn’t strain.
- Insulate the cabinet. Adding closed-cell foam or insulation inside the cabinet (around the plumbing) reduces heat loss on older tubs.
- Fix leaks and seal gaps. Even small water or air leaks waste heat continuously.
- Consider a heat-pump upgrade. If you’re replacing equipment, a heat pump can move several times more heat per watt than a resistance heater.
Is it cheaper to leave a hot tub on all the time?
For most owners who use their spa regularly, yes it is cheaper to keep the hot tub at a steady temperature than to cool it down and reheat it from cold. A well-insulated, covered tub loses heat slowly, so maintaining temperature uses less energy than the large burst of power needed to heat thousands of gallons back up from cold. The exception is if you genuinely won’t use the tub for weeks — in that case lowering the temperature (or using an “economy” mode) makes sense. We dig into the details here: Is it cheaper to run a hot tub all the time?
Frequently asked questions
How much does it cost to run a hot tub per month?
Most hot tubs cost about $20 to $50 per month in electricity, plus roughly $20 to $50 for chemicals, water, and filters. The all-in monthly running cost is typically $50 to $110, depending on your electricity rate, climate, and how well the tub is insulated.
How many kWh does a hot tub use per day?
A typical hot tub uses about 3 to 7.5 kWh per day, or roughly 100 to 300 kWh per month. Smaller, well-insulated tubs in mild climates use the least; large or poorly insulated tubs in cold weather use the most.
Is it expensive to run a hot tub in winter?
Winter is the most expensive time to run a hot tub because the heater must overcome a larger gap between the water temperature and the cold air. Your monthly cost can rise 30–50% or more in deep winter, which is why a quality cover, thermal blanket, and windbreak matter most in cold months.
Do hot tubs use a lot of electricity?
A hot tub uses a meaningful but manageable amount of electricity comparable to running a second refrigerator or a clothes dryer a few times a week. At 100 to 300 kWh per month, it’s usually one of the larger discretionary loads in a home, but efficient models and good insulation keep it modest.
What is the cheapest way to run a hot tub?
The cheapest way is to keep a well-insulated tub covered and at a steady, moderate temperature, clean the filters, block wind, and (if available) heat during off-peak hours. Upgrading a worn cover and adding a thermal blanket usually deliver the biggest savings for the least money.
How much does it cost to run a hot tub per year?
Expect about $500 per year on average to run a hot tub, including electricity, chemicals, water, and filters. The realistic range is roughly $350 for a small, efficient, lightly used spa to $1,100 or more for a large tub in a cold climate.
Does turning the temperature down really save money?
Yes. Because heat loss increases as the water gets hotter relative to the air, every degree you lower the setpoint reduces standby energy use. Dropping from 104°F to 100°F when the tub isn’t in use is an easy, no-cost way to trim the bill.
The bottom line
Running a hot tub costs the average U.S. household about $20 to $50 a month in electricity and roughly $500 a year all-in. The number you actually pay comes down to four things you can largely control: your electricity rate, your climate, your temperature setting, and the quality of your cover and insulation. Tighten those up — especially the cover — and a hot tub becomes one of the more affordable luxuries in the backyard.
Thinking about whether the ongoing cost is worth it for your household? Read Are Hot Tubs Worth It? Costs, Benefits & Who Should Buy, and if you’re still sizing your purchase, see What Size Hot Tub Should I Buy?
For more information on how to shop and compare hot tubs before purchasing please visit our hot tub buyer’s guide pages. You can also click on the pink boxes at the top right of every page to get a free local quotes from dealers in your area. Or, click our “Spa Buyer’s Consult” link above to get one-on-one expert advice on how to shop around for the best hot tubs available in your area.
