WattMath

Pool & Hot Tub Energy Calculator

Calculate the energy costs for your swimming pool pump, heater, and hot tub. Get personalized savings recommendations for variable-speed pumps, solar covers, and heat pump heaters.

Swimming Pool

Average pool: 15,000-25,000 gal

6-12 hours typical

Pool Heating

Hot Tub / Spa

Energy Rates

Pool Energy

Pools can add $50-300+ monthly to your energy bill. The pump is the biggest continuous draw, while heating (if used) is the most energy-intensive operation.

  • Pool pumps: 1,500-3,000+ kWh/year
  • Pool heating: varies widely by climate
  • Hot tubs: 2,500-4,000 kWh/year typical

How to Use

  1. Enter your pool size, pump type, and daily run time
  2. Add heating details if you heat your pool
  3. Check the hot tub box if you have one
  4. Enter your electricity rate and click Calculate

FAQ

Is a variable-speed pump worth it?

Usually yes. Variable-speed pumps cost $800-1,500 more but save 50-70% on pump energy. Most pay for themselves in 1-3 years and are now required by code in many states.

How long should I run my pool pump?

You need to turn over all pool water through the filter once per day. For most pools, this means 6-8 hours with a properly sized pump. Variable-speed pumps can run longer at lower speeds, which is more efficient and quieter.

What's the cheapest way to heat a pool?

Solar covers (free heating from sunlight) combined with a heat pump is the most economical. Heat pumps are 5-6x more efficient than gas or electric resistance heaters. A solar cover alone can raise water temp 10-15°F and cut heating costs 50-70%.