Hot Tub Running Cost Calculator (US)
The heater is 90% of your spa's electricity bill. Enter your details to get an honest daily, monthly and yearly number 鈥?and see exactly what a good cover is worth.
Typical US numbers (2026)
- Well-insulated 24/7 tub: 4鈥? kWh/day 鈫?$20鈥?5/month at $0.17/kWh
- Average tub: 6鈥?0 kWh/day 鈫?$30鈥?5/month
- Poorly insulated: 10鈥?4 kWh/day 鈫?$50鈥?0/month
- Heat-before-use (weekends): often the cheapest pattern for a 300鈥?00 gal tub: ~$5鈥?0 per heat-up
Where the money actually goes
- The cover is the #1 lever. A waterlogged or thin cover can double your bill. A quality 5" tapered cover typically pays for itself in one heating season.
- Wind exposure matters. An uncovered cabinet side in wind can strip heat faster than the heater replaces it.
- Temperature setting: every degree lower saves roughly 2鈥?% of heating energy. 101掳F vs 104掳F is a real difference over a month.
- Heat-before-use vs always-hot: heating 350 gallons from 70掳F to 102掳F takes ~8鈥?0 kWh (about $1.50). If you soak twice a week, heat-on-demand usually beats 24/7 holding 鈥?if you soak daily, keep it hot.
Frequently asked questions
How much does it cost to run a hot tub per month in the US?
A well-insulated 24/7 tub costs $20鈥?5/month; an average one $30鈥?5; a poorly insulated older tub $50鈥?0. Heat-before-use patterns often cost less for light users.
Is it cheaper to keep my hot tub hot all the time?
If you soak 3+ times a week, yes 鈥?reheating from cold costs 8鈥?0 kWh each time. If you use it once a week or less, heat-before-use wins.
Why is my electric bill so much higher than these numbers?
Check the cover first (saturated foam loses insulation), then the heater element (a failing element short-cycles), then your actual kWh rate on the bill 鈥?peak rates can be double the average.