Pool Cost Calculator

Whichever size you pick also decides how much you'll spend filling it and how much chemical each dose takes. These are popular sizes, with water averaging 4.5 feet deep:

A round or oval pool holds less water than a rectangle with the same length and width, so its gallon estimate uses 5.9 instead of 7.48.

The bill from your water utility lists a price per 1,000 gallons, and many bills stack sewer charges on top of that. For example, if your pool holds 17,200 gallons, divide that by 1,000, multiply by the price on your bill and add any sewer charge.

A hose is slow. To picture it, say it takes the hose 40 seconds to fill a 5-gallon bucket. That same hose would need roughly 33 hours to put 15,000 gallons in a pool.

The water doesn't stop there. Evaporation alone can take about a quarter inch a day, and wind or hot weather speeds that up, a figure from Latham Pool.

Your pump circulates water through the filter so it stays clean. What you want is one turnover a day, meaning every gallon passes through the filter once. Usually that takes around 8 hours, then another 1 to 2 hours when it's hot or the pool got heavy use.

A standard single-speed pump pulls about 1,725 watts. Run it 8 hours and you're at about 13.8 kWh a day. The EIA puts the US average power price at 18.16 cents per kWh, so multiply your daily kWh by that price to get the daily cost.

Heating takes a lot of energy, since 8.34 BTU warms just one gallon of water by 1 degree F. For every unit of power a heat pump uses, it delivers about 5 units of heat. A gas heater converts roughly 82% of its fuel into heat.

A larger pool, or a bigger jump in temperature, means a higher heating bill either way.

Any pool needs steady chemical doses to keep the water in balance. Doses are measured in parts per million (ppm), a count of how much of a chemical is dissolved in the water. That's the reading a test strip or kit gives you.

The bigger the pool, the bigger each dose. For 10,000 gallons, lifting free chlorine by 1 ppm takes roughly 10 fluid ounces of liquid chlorine at 12.5%. Shocking it upward by 10 ppm calls for about 102 fluid ounces. With a 20,000-gallon pool, double both amounts.

If you're going with a salt system, aim higher on stabilizer, at 70 to 80 ppm, instead of the 30 to 50 ppm other pools use. Keep salt at whatever level the cell manufacturer specifies, often somewhere between 3,000 and 3,500 ppm.