How Many Gallons in a 27 Ft Round Pool?
Water in the pool
19,274 gallons
Round, 27 ft across, filled to a 54 in wall, which is 4.5 ft. Flat bottom, so the average depth is the wall height.
Filling this pool on a garden hose takes 1.7 days of continuous water. Most water utilities sell a bulk fill, and some will not meter a pool fill through the sewer charge if you call first, which is worth more than the hose.
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How that number is worked out
These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.
- Pool shapeRound
- Length or diameter27 ft
- Width27 ft
- Shallow end depth4.5 ft
- Deep end depth4.5 ft
- Fill rate8 gal/min
- Turnover target8 hours
Water in the pool19,274 gallons
Filling this pool on a garden hose takes 1.7 days of continuous water. Most water utilities sell a bulk fill, and some will not meter a pool fill through the sewer charge if you call first, which is worth more than the hose.
| Surface area | 572.6 sq ftpi r squared on the diameter |
|---|---|
| Average depth | 4.5 ftmidpoint of shallow and deep |
| Volume | 2,576.5 cu ft7.48 gallons in each |
| Water weight | 80.4 tons160,742 lb |
| Fill time | 40.2 hoursat 8 gallons a minute |
| Pump for turnover | 40.2 gal/minwhole volume once in 8 hours |
| Heater to raise 10 degrees | 1,607,000 BTU8.34 BTU per gallon per degree |
| Liquid chlorine for a 10 ppm shock | 1.54 gal12.5 percent, sold in gallon jugs, so buy 2 |
| Salt to reach 3,200 ppm | 515 lb13 bags at 40 lb, from zero |
The material list this produces
| Water, gallons | 19,274 |
|---|---|
| Liquid chlorine 12.5 percent, gal | 2 |
| Salt, 40 lb bags | 13 |
| Pump, gal/min | 41 |
Diameter compared
Same wall height as this page, across round diameters from 8 to 33 feet. Water goes up with the square of the diameter, so doubling the diameter holds four times the water.
| Diameter | Water in the pool | Surface area | Fill time |
|---|---|---|---|
| 8 ft | 1,693 gallons | 50.3 sq ft | 3.5 hours |
| 12 ft | 3,808 gallons | 113.1 sq ft | 7.9 hours |
| 15 ft | 5,949 gallons | 176.7 sq ft | 12.4 hours |
| 18 ft | 8,567 gallons | 254.5 sq ft | 17.8 hours |
| 21 ft | 11,660 gallons | 346.4 sq ft | 24.3 hours |
| 24 ft | 15,229 gallons | 452.4 sq ft | 31.7 hours |
| 27 ft | 19,274 gallons | 572.6 sq ft | 40.2 hours |
| 30 ft | 23,795 gallons | 706.9 sq ft | 49.6 hours |
| 33 ft | 28,792 gallons | 855.3 sq ft | 60 hours |
What else matters here
Forty hours to fill on a hose. 515 pounds of salt from zero if it runs a chlorine generator. A heater has to push about 1.6 million BTU into it to raise the whole pool ten degrees.
The water weighs eighty tons. That is spread across 573 square feet, about 280 pounds on every square foot.
What this calculator assumes
- A cubic foot of water is 7.48 gallons and a gallon weighs 8.34 pounds. Those two numbers do all the work on this page.
- Average depth is taken as the midpoint of the shallow and deep ends. That is exact for a pool with one straight slope between them and slightly generous for a pool with a flat shallow shelf and a hopper, which is the safer way for it to be wrong when you are buying chemicals.
- A round pool uses the diameter and ignores the width. An oval is figured as an ellipse, which is length times width times pi over four, not as a rectangle.
- Turnover is the time the pump takes to move the whole volume once. Eight hours is the common residential target and some health codes for public water are stricter, so check yours before you size a commercial pump off this.
- Liquid chlorine trade percent is defined so that one gallon of it raises ten thousand gallons of water by that many parts per million. One gallon of 12.5 percent raises 10,000 gallons by 12.5 ppm, which is where the dose row comes from rather than a chart.
- Salt is figured from zero to 3,200 ppm, which is the middle of the range most chlorine generators want. A pool that already has salt in it needs a test first, because salt only leaves with the water.
Questions people ask
How is the water weight worked out?
Gallons times 8.34 pounds, which is what a gallon of water weighs.
Why 54 inches and not 52?
The taller wall is the same idea as 52 over 48: more water on the same footprint. Change the depth on the calculator to 4.33 for a 52 inch wall and the volume drops by about 730 gallons.
The pool volume calculator takes any dimensions you like and hands back the same list.