How much does a hot tub cost to run? The real electricity numbers

At the US average residential rate of 18.05¢/kWh, a standard 300-gallon hardshell hot tub uses 300 to 500 kWh per month in a temperate climate. That's $54 to $90 on the electric bill. In a cold-climate winter, that figure can push past 700 kWh and $130 per month. A poorly insulated tub or an inflatable model often costs even more despite drawing fewer peak watts.

Most of that electricity goes to holding the water at temperature around the clock, not to the minutes someone spends in the tub. The heater cycles on and off to maintain 100 to 104°F. The circulation pump runs 6 to 12 hours daily for filtration. Both work harder when outdoor temperatures drop. The tub is always heating, whether or not anyone is in it.

Two loads account for nearly all of it. The heater element, typically rated 4,000 to 6,000 watts on a 240-volt circuit, does the heavy work. A Jacuzzi J-335 draws 5,000 watts at peak. A Cal Spas Atlas pulls 6,000. But the heater doesn't run continuously. It cycles on and off to hold the setpoint, with total on-time determined by insulation quality and the gap between the water temperature and outdoor air.

In mild weather around 70°F, the heater might accumulate 2 to 4 hours of actual on-time per day. In a Minnesota January at 10°F, it can run 8 hours or more. The circulation pump adds 200 to 500 watts and runs 6 to 12 hours daily for filtration and chemical distribution. Smaller than the heater's contribution, but not trivial: a 300-watt pump running 10 hours per day adds about 90 kWh and $16 to the monthly bill at the national average rate.

Winter is when hot tub costs spike. The heater fights a larger temperature differential between the 102°F water and the outdoor air. A tub maintaining temperature when it's 70°F outside loses heat slowly. The same tub at 15°F outside loses heat roughly three times faster, and the heater runs roughly three times longer to compensate.

For a mid-range 4,500-watt spa at 18.05¢/kWh, the seasonal pattern looks like this. In summer with mild ambient temperatures, expect roughly 250 to 350 kWh per month, or $45 to $63. In spring and fall, that climbs to 350 to 500 kWh, or $63 to $90. In a cold-climate winter, 550 to 800 kWh is common, or $100 to $144. Year-round, a typical owner in a temperate state pays about $900 to $1,200 annually. In cold-winter states, $1,200 to $1,600.

A hardshell hot tub from brands like Hot Spring, Jacuzzi, or Caldera uses rigid polyurethane foam insulation and a tight-fitting cover. This is the most energy-efficient design. Monthly costs typically land between $50 and $100 depending on climate and setpoint.

An inflatable hot tub from Intex, Coleman, or Bestway trades insulation for portability. The walls are vinyl with an air gap instead of rigid foam. The heater, usually 1,300 to 1,500 watts on a standard 120-volt plug, works constantly because the tub sheds heat through the thin walls. Despite drawing fewer peak watts than a hardshell, an inflatable often costs the same or more per month because it never stops losing ground. Expect $60 to $120 monthly.

A swim spa pushes the range higher. These hold 1,500 to 2,500 gallons and run jet pumps for the swim current on top of the heating load. Monthly electricity for a swim spa ranges from $100 to $200 depending on jet usage and the larger surface area losing heat.

The same tub using 450 kWh per month costs dramatically different amounts depending on where the house sits. State residential rates in 2026 range from 11.9¢/kWh in Louisiana to 41.2¢/kWh in Hawaii. At 450 kWh per month, that's $54 in Louisiana, $67 in Texas at 14.8¢, $81 at the national average, $129 in Connecticut at 28.7¢, $141 in California, and $185 in Hawaii.

A hot tub in Hawaii costs more than three times what the same tub costs in Louisiana. If your state rate runs above 25¢/kWh, the quality of your cover and insulation matters twice as much because every wasted kWh costs more. Check your state's current residential rate on the state rate pages to see where your numbers fall.

Every efficiency lever for a hot tub comes back to reducing the heater's runtime. The heater is the bill. The pump and controls are rounding errors by comparison.

• Upgrade the cover.A well-insulated, tight-sealing cover is the single largest lever. Heat escapes primarily through the water surface. A quality cover paired with a thermal floating blanket underneath cuts heating costs 50 to 70%, per DOE estimates on pool and spa heating. On a $100/month tub, that's $50 to $70 saved.
• Lower the setpoint between uses. Dropping from 104°F to 95°F when the tub sits idle for a few days shrinks the temperature gap with outdoor air and reduces heater runtime 20 to 40%. Most modern controllers can schedule this automatically.
• Run the circulation pump on a timer. A pump running 12 hours daily when 6 hours would suffice wastes about 55 kWh and $10 per month in electricity. Some newer tubs allow custom circulation schedules.
• Block wind exposure. A tub in a wind-exposed location loses heat faster through convection and surface evaporation. A privacy fence, gazebo, or windbreak can noticeably reduce heater runtime in exposed installations.
• Maintain water chemistry. Scale buildup on the heating element reduces heat transfer efficiency and forces longer cycles to reach the same temperature. Regular descaling keeps the heater working at its rated output.

Tub wattage varies by brand and model. Insulation quality varies by construction type. Climate varies by zip code. Your state's rate ties it all together. Plug in your specifics below to see what the tub actually costs at your rate rather than a national average that may not match your situation.

For a closer look at heater versus pump draw and how each variable moves the total, the hot tub appliance page breaks it down component by component. If the hot tub is part of a broader bill spike and you're not sure it's the cause, the high-bill diagnostic walkthrough can help isolate which appliance is responsible.