Enter the desired temperature rise, the size of the pool, and the heater output into the calculator to determine the time to heat the pool.

Pool Heat Time Formula

The following formula is used to calculate the total time it takes to heat a pool.

T = S * 8.33 * t / HP

  • Where T is the heat time in hours
  • S is the size of the pool in gallons
  • t is the desired temperature rise (F)
  • HP is the heater output power (BTUs/hr)

Pool Heat Time

How long does it take to heat a pool?

The time it takes to heat a pool depends on three factors:

  1. The size of the pool. The larger the pool and larger the body of water the more time it will take to heat the pool.
  2. The needed temperature rise. The more temperature difference you need to acheive the longer it will take.
  3. The power output of the heater. A more powerful heater will reduce the time it takes to heat the pool.

Example Problem

How to calculate pool heat time?

  1. First, determine the size of the pool.

    For this example, the pool has 30,000 gallons of water.

  2. Next, determine the temperature rise that needs to be achieved.

    For this problem, we would like to raise the temperature 20 degrees F from where it is now.

  3. Next, determine the power output of the heater.

    The power output for this heater is estimated to be 400,000 BTUs per hour.

  4. Finally, calculate the time to heat the pool.

    Using the formula above, the pool heat time is calculated to be:
    T = S * 8.33 * t / HP
    T = 30,000 * 8.33 * 20 / 400,000
    T = 12.495 hours