Pool & spa
Pool Heater Size Calculator
Heater size from surface area and the temperature rise you want, and how long it takes to get there.
Result
Most heat leaves a pool through its surface, which is why surface area matters more than depth and why a cover is the single most effective thing you can add. Wind, humidity and night air temperature all change the loss substantially, so treat this as a size band rather than a precise figure.
Get a Free Business AuditQuestions
About this calculator
Why does a cover matter so much?
Evaporation carries away most of the heat. A cover can cut heat loss by half to three quarters, which usually saves more than any heater upgrade.
Gas or heat pump?
Gas heats fast and works in cold weather, which suits occasional use. A heat pump costs far less to run but heats slowly and loses capacity as the air cools, which suits maintaining a temperature all season.
Is a bigger heater wasteful?
Not in running cost, since it simply runs for less time to deliver the same heat. It costs more to buy and may need a larger gas line.
The formula
energy = gallons x 8.34 x temperature rise; heater = energy / hours + surface loss
Put this calculator on your site
Free to embed. Paste this where you want it to appear. It stays up to date automatically because it loads from BDEVY.
Please keep the attribution line. It is the only thing we ask in return.
Estimating is the easy part
The jobs you never hear about cost more than the ones you mis-measure. BDEVY builds the marketing, systems and automation that bring them in.