The maths
- Area = π × 7.5² = 176.7 sq ft
- Volume = 176.7 × 4 = 707 cu ft
- 707 cu ft × 7.48 gal per cu ft
= 5,290 US gallons
Real pools vary: water levels sit a few inches below the wall top, floors slope and corners are rounded. If your pool’s depth differs, adjust it in the volume calculator.
Frequently asked questions
How many gallons is a 15 ft round pool?
About 5,290 US gallons (20,016 litres) with 4 ft of water.
How much salt does a 15 ft round pool need?
About 141 lb (64 kg) to bring fresh water to 3,200 ppm, or 4 bags of 40 lb. Check your salt cell’s target first.
How much chlorine does a 15 ft round pool need?
Each +1 ppm of free chlorine takes about 7 fl oz of 10% liquid chlorine. With stabilizer at 40 ppm, keep free chlorine around 4.6 ppm.