The maths
- Average depth = (3.5 + 6) ÷ 2 = 4.75 ft
- Volume = 30 × 15 × 4.75 = 2,138 cu ft
- 2,138 cu ft × 7.48 gal per cu ft
= 15,990 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 × 30 ft pool?
About 15,990 US gallons (60,527 litres) with 3.5 ft shallow end, 6 ft deep end.
How much salt does a 15 × 30 ft pool need?
About 427 lb (194 kg) to bring fresh water to 3,200 ppm, or 11 bags of 40 lb. Check your salt cell’s target first.
How much chlorine does a 15 × 30 ft pool need?
Each +1 ppm of free chlorine takes about 20 fl oz of 10% liquid chlorine. With stabilizer at 40 ppm, keep free chlorine around 4.6 ppm.