Below are links to two swimming pool energy and water savings calculators:
Swimming Pool Energy & Water Savings Calculator App for iPhone, iPad, and Android units. Download now for free at www.poolsavingscalculator.com
Below is a link to a very useful Pool Energy Saving Calculator produced by Energy Experts, that is an incredibly useful tool in helping you see just how much energy your pool is using.
Heat transfer from both indoor and outdoor pools occurs primarily through evaporative loss. For an outdoor pool, there are also losses and gains due to radiation to the sky, convection and solar gains. For indoor pools, heat loss is almost entirely due to evaporative losses. Energy is also required to heat refill water.
The "Pool Energy Use Calculator" can be used to optimize energy use and estimate how much can be saved by modifying setpoints, cover use, and heating schedules from the base case.
Note that fan energy, pumping energy, losses across the building envelope, and losses due to dehumidification by ventilation are not calculated. You will need to do separate calculations for these items.