How many gallons in a 20×40 ft rectangle pool?
A 20×40 ft rectangle in-ground pool holds about 29,900 gallons (113,300 liters) with 5 ft of water.
By water depth
| Water depth | US gallons | Liters |
|---|---|---|
| 4 ft (48 in) | 23,900 | 90,600 |
| 5 ft (60 in) | 29,900 | 113,300 |
| 5.5 ft (66 in) | 32,900 | 124,600 |
Formula: 40 × 20 × avg depth × 7.48. Measure the water, not the wall: water usually sits 4–6 inches below the top rail. For a sloped floor use the average of shallow and deep depth.
At 5 ft of water
Dose this pool: full chemical calculator · liquid chlorine · salt
Other rectangular pool sizes
12×24 ft rectangle · 14×28 ft rectangle · 15×30 ft rectangle · 16×32 ft rectangle · 16×36 ft rectangle · 18×36 ft rectangle
Questions pool owners ask
How many gallons are in a 20×40 ft rectangle pool?
About 29,900 gallons at 5 ft (60 in) of water. At 4 ft it holds about 23,900 gallons and at 5.5 ft about 32,900. Formula: 40 × 20 × avg depth × 7.48.
How much salt does a 20×40 ft rectangle pool need?
Starting from fresh water, about 799 lb of pool salt (20 × 40 lb bags) reaches 3,200 ppm at 5 ft of water. Add 80–90% first, then test after 24 hours.
How much liquid chlorine for a 20×40 ft rectangle pool?
Raising free chlorine by 1 ppm takes about 1.2 qt (38 fl oz) of 10% liquid chlorine, or 1.94 qt (62 fl oz) of 6% bleach.
How long does it take to fill?
With a garden hose at about 10 gallons per minute, roughly 50 hours. Two hoses halve that.