How many gallons in a 18×36 ft rectangle pool?
A 18×36 ft rectangle in-ground pool holds about 24,200 gallons (91,700 liters) with 5 ft of water.
By water depth
| Water depth | US gallons | Liters |
|---|---|---|
| 4 ft (48 in) | 19,400 | 73,400 |
| 5 ft (60 in) | 24,200 | 91,700 |
| 5.5 ft (66 in) | 26,700 | 100,900 |
Formula: 36 × 18 × 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 · 20×40 ft rectangle
Questions pool owners ask
How many gallons are in a 18×36 ft rectangle pool?
About 24,200 gallons at 5 ft (60 in) of water. At 4 ft it holds about 19,400 gallons and at 5.5 ft about 26,700. Formula: 36 × 18 × avg depth × 7.48.
How much salt does a 18×36 ft rectangle pool need?
Starting from fresh water, about 647 lb of pool salt (17 × 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 18×36 ft rectangle pool?
Raising free chlorine by 1 ppm takes about 31 fl oz of 10% liquid chlorine, or 1.57 qt (50 fl oz) of 6% bleach.
How long does it take to fill?
With a garden hose at about 10 gallons per minute, roughly 40 hours. Two hoses halve that.