How much heat the water needs
The kWh result is heat delivered to the water. It is not the same as electricity consumption.
Calculators
Energy and time
Pool heating calculator: energy and time
Enter volume, starting and target temperatures, and heater output. The calculator estimates the heat required and warm-up time.
Calculator
Estimate heating energy and time
Enter the heating output delivered to the water, not electrical input power. The assumed loss percentage provides a rough allowance for wind, air temperature, evaporation and cover use.
Understanding the result
How to interpret your calculation
Higher output can shorten heating time
Only if flow, air temperature and other conditions allow the heater to deliver that output.
Keep the insulated cover in place
Reducing evaporation and overnight cooling keeps more of the supplied heat in the water.
Heating time is an estimate
Actual time depends on heater performance, weather, wind, the cover and air temperature.
Related guides
Check the conditions that affect heating
FAQ
Frequently asked questions
Does the kWh result mean the same number of kWh of electricity?
No. It is the heat the water needs. Electricity use depends on heater type, efficiency and actual operating conditions.
How should I choose the heat-loss percentage?
Use it to compare scenarios, not as a measured fact. Compare covered and uncovered operation, and get a professional sizing calculation before buying equipment.
Why might heating take longer in practice?
The heater may not deliver its rated output, while the pool is losing heat at the same time. Flow, air temperature, wind, overnight cooling and cover use can all change the result.
Can I use this for solar heating?
The water’s heat requirement still applies. Solar output varies considerably, though, so a constant output value is only a simplified scenario.