How Much Does a Hot Tub Cost to Run? Real 2026 Monthly Numbers

Short answer: a well-insulated hot tub costs $30-$70 per month in electricity in a moderate climate, rising to $80-$120 for a large tub in a cold climate. Add $15-$30 per month for water care chemicals and about $100-$200 per year for filters and cover upkeep. Total realistic running cost: $50-$150 per month. The two variables that dominate everything else are insulation quality and cover condition - not jet count, not pump horsepower.

Hot tub glowing in a backyard at night
Most of the electricity bill is heat loss, not heating - which is why insulation beats every other spec.

The Monthly Cost Breakdown

Cost item Monthly range Notes
Electricity (heating) $25-$90 Dominated by insulation + climate
Electricity (pumps) $5-$15 Jets and filtration cycles
Water care chemicals $15-$30 Chlorine/bromine, pH, shock, clarifier
Water replacement $3-$8 Refill every 3-4 months
Filters & cover (amortised) $8-$17 New filters yearly, cover every 4-5 years
Total $50-$150 Moderate climate, average use

Cost by Tub Size

Tub size Water volume Monthly electricity
2-3 person 700-1,100 L $30-$50
4-5 person 1,200-1,600 L $45-$75
6-7 person 1,700-2,300 L $60-$100
Swim spa (dual zone) 5,000-8,000 L $100-$200

Volume matters, but less than most people assume - roughly linearly, not dramatically. Going from a 4-person to a 6-person tub adds about 25-30% to the heating bill, not 100%.

Electricity Rates: Run Your Own Number

At the US average residential rate your tub sits in the middle of the ranges above, but rates vary hugely by state and season. The EIA's breakdown of household electricity use shows how a spa compares with other big loads - a hot tub typically lands between a refrigerator and central air conditioning. Quick formula:

  • kWh/month = (heater watts × heating hours/day × 30) ÷ 1000
  • A 5.5 kW heater running 1.5 hours/day = about 250 kWh/month
  • Multiply kWh by your rate: 250 × $0.17 = $42.50/month
Hot tub cover in place reducing heat loss
A fitted, intact cover is the single highest-return purchase in hot tub ownership.

What Actually Drives the Bill

  • Cover quality (biggest factor). A worn, waterlogged cover can double heat loss. Replacement every 4-5 years pays for itself within a year.
  • Insulation. Full foam or thermal-wrap insulation on the shell and cabinet cuts standby loss dramatically versus a bare acrylic shell.
  • Outdoor temperature. A tub heating against -5°C air loses several times more heat than the same tub at 20°C.
  • Set temperature. Dropping from 40°C to 38°C saves roughly 10-15% on heating.
  • Filtration scheduling. Modern tubs heat during filtration cycles. Two longer cycles beat six short ones.
  • Leaks and failing heaters. A pump seal leak that keeps the heater running is the classic silent bill-inflator.

Seven Ways to Cut the Bill

  • Keep the cover on every time you get out - no exceptions.
  • Add a floating thermal blanket under the hard cover (about $30, cuts evaporation loss).
  • Lower the set point 2°C when the tub will sit unused for a week or more.
  • Never use "economy" mode in freezing weather unless the tub is designed for it - freeze damage costs far more.
  • Clean filters monthly; clogged filters make pumps run longer.
  • Fix the cabinet: seal gaps and repair insulation panels after service work.
  • Consider a heat pump if you soak daily - higher upfront cost, 50-70% lower heating energy.

Comparing ownership costs across price bands? The 2026 hot tub cost guide breaks down purchase price, installation and running costs together. If you are weighing a tub against a swim spa, the running-cost comparison is in our home water fitness guide.

Energy-Efficient Tubs, Factory Direct

Every tub in our hot tubs & spas collection ships with full insulation and a fitted cover - the two things that decide your monthly bill. Browse 2-4 person and 5-7 person models with free shipping on qualifying orders.

Related Guides

Frequently Asked Questions

How much does a hot tub cost per month in electricity?

Typically $30-$70 for a mid-size, well-insulated tub in a moderate climate, and $80-$120 for a large tub in cold conditions. Cover condition and insulation quality matter more than tub size.

How much does it cost to heat a hot tub?

Heating is roughly 70-80% of the electricity bill - about $25-$90 per month. Each 1C you lower the set point saves roughly 5-7% of heating energy.

Is it cheaper to leave a hot tub on all the time?

Yes, in almost all cases. Maintaining temperature uses less energy than repeatedly reheating from cold, and it prevents freeze damage. Lower the set point for long absences rather than shutting it down.

Do hot tubs use a lot of electricity?

A modern insulated 240V tub uses about as much as a space heater running in cycles - comparable to a refrigerator, well below central air conditioning. Poorly insulated or uncovered tubs can use several times more.

Back to blog