How many gallons is a 15 foot round above ground pool?

A 15-foot round pool filled to 48 inches holds roughly 5,300 gallons. Filled to 52 inches it holds about 5,700 gallons. The exact figure depends on your actual water depth, which is typically a few inches below the wall height.

How long does it take to fill an above ground pool with a garden hose?

A standard garden hose delivers roughly 8 to 12 gallons per minute. At 10 gallons per minute, a 5,300-gallon pool takes about 9 hours to fill. Larger pools can take a full day or more, which is why some homeowners have water delivered by truck instead.

How much sand do I need under an above ground pool?

A typical base layer is 2 inches deep across the pool footprint plus about a foot of margin. For a 15-foot round pool that works out to roughly 1.5 tons of sand. Sand is a cushioning layer over already-level ground, not a way to correct a slope.

How much does it cost to fill an above ground pool with water?

Water is billed per unit rather than per gallon and rates vary by provider, so cost depends entirely on your local utility. For most homeowners the initial fill is a modest one-time expense compared with the pool itself. Check your water bill for your rate per unit, or ask about a pool-fill allowance.

Above Ground Pool Gallons Calculator | How Many Gallons Is My Pool?

Why the gallon count actually matters

It isn't trivia. That number drives four decisions:

Chemical dosing

Every chlorine, shock, and balancer instruction is written per volume of water. Guess the gallons and you'll over- or under-treat the pool all season.

Pump and filter sizing

A pump should turn the full volume over roughly once every 8 hours. Undersize it and the water never really clears.

Fill planning

A 24-foot pool on a garden hose can run more than a full day. If you're on a well, that matters — a lot of homeowners have the first fill trucked in instead.

Ground load

Water weighs about 8.3 pounds per gallon. A 15-foot pool is over 40,000 pounds. That's why the base under it isn't a detail.

That last one is the one people underestimate. Forty thousand pounds sitting on dirt that isn't level or compacted is how above ground pools fail — slowly, over one season, and then all at once. Here's how to check your yard's slope →

Common pool sizes at a glance

Pool Size	Gallons (48″ water)	Approx. Fill Time
12 ft round	~3,400	~6 hours
15 ft round	~5,300	~9 hours
18 ft round	~7,600	~13 hours
24 ft round	~13,500	~22 hours
12 x 24 oval	~6,800	~11 hours

Fill times assume a standard garden hose at about 10 gallons per minute. Yours may run faster or slower.

A note on filling in the Central Valley

Summer here is hot and dry, and an uncovered pool loses real water to evaporation — enough that you'll be topping off regularly, not just once. A cover pays for itself fast, both in water and in the chemicals you'd otherwise be replacing.

If you're on a domestic well rather than city water, plan the first fill carefully. Drawing thousands of gallons in one stretch is hard on a well pump. Trucked-in water for the initial fill is common around here and worth pricing out.

Common Questions

Pool volume, answered

How many gallons is a 15 foot round pool?

About 5,300 gallons at 48 inches of water depth, or roughly 5,700 at 52 inches. Depth matters more than people expect — four extra inches adds hundreds of gallons.

Should I use my wall height or my water depth?

Water depth. A pool with a 52-inch wall typically fills to about 48 inches, since you never fill to the very top. Using wall height will overstate your volume.

How much does it cost to fill?

Depends entirely on your water provider's rate, since water is billed per unit rather than per gallon. For most homeowners it's a modest one-time cost next to the pool itself. Some utilities offer a pool-fill allowance — worth a phone call.

How much sand goes under the pool?

Typically a 2-inch layer across the footprint plus a margin — about 1.5 tons for a 15-foot round. And to be clear: sand is a cushion over level ground, not a way to fix a slope. Piling sand on the low side will fail.

Do I need a permit for a pool this size?

In California, any pool holding water deeper than 18 inches needs a permit, plus an approved safety barrier. That's every pool in the table above. Full permit guide →

How many gallons is your above ground pool?