Volume by water depth
| Water depth | US gallons | Litres |
|---|---|---|
| 44 in of water | 9,500 gal | 35,960 L |
| 46 in of water | 9,930 gal | 37,600 L |
| 48 in of water | 10,360 gal | 39,230 L |
Formula: 21 × 21 × 3.83 ft × 5.87 = 9,932 gal.
How many gallons is a 21 ft round × 52 in above-ground pool?
A 21 ft round above-ground pool with 52 in walls holds about 9,930 US gallons (37,600 L) when filled to 46 in of water, about 6 in below the top rail. Volume depends on the water depth, not the wall height, so measure your water and check the table.
Measure your own water depth
9,932gal
About 37,597 L
Average depth 3.8 ft
Formula: diameter² × average depth × 5.87.
- Pool shapes are never perfect. Treat this as within about 10%, and check it once by adding a known amount of salt or stabilizer and testing the change.
- Use this volume: Chlorine pH Shock All-in-one
Save this test and get reminded when it is time to retest.
Pool Calc for iPhoneComing soon to the App StoreDoses for this pool
| Job | Amount |
|---|---|
| Raise chlorine 1 ppm | 13 fl oz of 10% liquid chlorine |
| Stabilizer 0 → 30 ppm | 2.5 lb |
| Salt 0 → 3,200 ppm | 267 lb (6.7 bags) |
Full dose tables for a pool this size: liquid chlorine for 10,000 gallons, salt and stabilizer. Or put 9,932 gallons straight into the pool chemical calculator.
Check the number once
Manufacturer capacities are usually given at a stated fill level, and liners stretch. To confirm your real volume, add a known amount of salt or stabilizer and see how much the test reading moves: the volume that explains that change is your pool.
Questions
How many gallons does a 21 ft round × 52 in pool hold?
About 9,930 gallons at 46 in of water.
How many litres is a 21 ft round × 52 in pool?
About 37,600 L at 46 in (117 cm) of water.