Pool Calculator
This pool calculator finds out the amount of water that goes into a swimming pool of a specific size.
Water volume21,065 US gallons79,740 litres · 2,816 cu ft
Surface area512 sq ft47.566 m²
Average depth5.5 ft3 ft to 8 ft
Weight of the water87.9 US tons79,740 kg
Pump flow for a 8-hour turnover43.89 gal/min166.1 l/min
Filter area needed2.93 sq ftsand filters run about 15 gal/min per sq ft
Chlorine to raise by 1 ppm2.81 ozof pure chlorine, by weight
Volume in 10,000-gallon units2.107most pool chemicals are dosed per 10,000 gallons
Time to fill at 10 gal/min35:07a typical garden hose
The method
volume = area × average depth
Average depth, not maximum
A pool that runs from 3 to 8 feet averages 5½ feet, so it holds about a third less than the deep end suggests. Getting this wrong throws off every chemical dose, because they are all quoted per volume.
Freeform pools never fill their bounding rectangle. Taking 85% of length × width is the usual approximation for a kidney shape, and it is worth checking against the actual fill volume once you know it.
Turnover is the figure the plant is sized on: most codes want the entire volume passed through the filter in six to eight hours, which for a typical residential pool means 40–60 gallons a minute.