A 240 V hot tub draws about 4,000 watts while heating (roughly 1,500 W for 120 V plug-in spas up to 7,500 W with heater and jets running). Averaged over a day, most use about 3-8 kWh.
- Running watts
- 4,000 WTypical; 1,500–7,500 W across models
- Starting watts
- NoneNo motor surge
- Per day
- 4.8 kWh24 h of use, cycling
- Current
- 16.7 AAt 240 V while running
Figures checked against DOE, ENERGY STAR and manufacturer data on . Your model's label is the final word.
Watts by model and setting
Most hot tub models draw between 1,500 and 7,500 W while running; a typical one draws about 4,000 W. Heater (~4 kW) cycles about 5% of the day on average: 4,000 W x 24 h x 0.05 = 4.8 kWh. Hot Spring's estimates for a mid-size spa range from 100 kWh/month in Miami to 210 kWh/month in Chicago (about 3.3-7 kWh/day); colder climates and heavy use push it higher.
- Heater size: 240 V spas typically use 4-6 kW heaters; 120 V plug-and-play spas about 1.5 kW
- Jet pumps (often 2+ HP each) add a large load when running
- Outdoor temperature, cover quality and insulation drive how often the heater runs
- Set temperature and how often and long the tub is used
Running a hot tub on backup power
This is a 240 V appliance. It needs a generator with a 240 V outlet or a transfer switch or interlock installed by a licensed electrician; most portable power stations only supply 120 V.
- A hot tub is not an outage essential; in freezing weather the priority is just keeping water circulating so plumbing doesn't freeze
- 240 V spas are hardwired with a 50 A GFCI disconnect; any generator connection must go through an electrician-installed transfer switch, never a backfed outlet
- Portable power stations cannot meaningfully run a 4-6 kW heater; size any generator for the heater plus the jet pump's starting surge
- Run a gas generator outdoors only, at least 20 feet from doors, windows and vents; carbon monoxide from generators kills. Use heavy-duty extension cords or a professionally installed transfer switch, never backfeed a home outlet.
Add it to the generator calculator
Questions people ask
How much does it cost to run a hot tub per month?
Hot Spring estimates a mid-size spa uses about 100-250 kWh a month depending on climate, or roughly $10-30 a month at typical US rates.
Can I run my hot tub on a generator?
Only a large generator with 240 V output (often 7,500 W+ for heater plus jets) connected through a professionally installed transfer switch. In an outage it is usually better to keep it covered and drain it if a long freeze is coming.