A 24 ft round above-ground pool with a 52 in. wall holds about 13,000 gallons, and an 18 ft round pool about 7,300 gallons. The charts below give every common size for 48, 52 and 54 in. walls, assuming the water sits 6 in. below the top. For an inground, kidney or freeform pool, use the pool volume calculator instead.
Round above ground pool gallons chart
Find your pool’s diameter in the left column and read across to your wall height. The water depth under each wall height is what the numbers use.
| Pool size | 48 in. wall42 in. of water | 52 in. wall46 in. of water | 54 in. wall48 in. of water | Liters52 in. wall |
|---|---|---|---|---|
| 12 ft round | 3,000 gal | 3,200 gal | 3,400 gal | 12,000 L |
| 15 ft round | 4,600 gal | 5,100 gal | 5,300 gal | 19,000 L |
| 18 ft round | 6,700 gal | 7,300 gal | 7,600 gal | 28,000 L |
| 21 ft round | 9,100 gal | 9,900 gal | 10,400 gal | 38,000 L |
| 24 ft round | 11,800 gal | 13,000 gal | 13,500 gal | 49,000 L |
| 27 ft round | 15,000 gal | 16,400 gal | 17,100 gal | 62,000 L |
| 30 ft round | 18,500 gal | 20,300 gal | 21,200 gal | 77,000 L |
| 33 ft round | 22,400 gal | 24,500 gal | 25,600 gal | 93,000 L |
Oval above ground pool gallons chart
Oval sizes are listed width × length, the way they’re usually sold.
| Pool size | 48 in. wall42 in. of water | 52 in. wall46 in. of water | 54 in. wall48 in. of water | Liters52 in. wall |
|---|---|---|---|---|
| 12 × 24 ft oval | 5,900 gal | 6,500 gal | 6,800 gal | 25,000 L |
| 15 × 30 ft oval | 9,300 gal | 10,100 gal | 10,600 gal | 38,000 L |
| 16 × 32 ft oval | 10,500 gal | 11,500 gal | 12,000 gal | 44,000 L |
| 18 × 33 ft oval | 12,200 gal | 13,400 gal | 14,000 gal | 51,000 L |
Many oval above-ground pools have straight sides and rounded ends rather than a true ellipse. Those hold a little more water than this chart shows, so if your oval has long straight sides, treat these numbers as the low end.
How much water is in your pool, not on the box
Above-ground pools are filled below the top of the wall. The water line usually sits about 6 in. down, so a 52 in. wall holds about 46 in. of water. That’s why the chart uses water depth: working from the full wall height would overstate your gallons by about 13%.
If your pool has a marked fill line or you keep the water higher or lower, measure from the water surface to the floor and enter it in the calculator above with “I know my water depth.”
How the numbers are worked out
Every figure here uses the same formula as our main volume calculator:
- Round: 3.1416 × (diameter ÷ 2)² × water depth × 7.48 gallons per cubic foot
- Oval: 3.1416 × (length ÷ 2) × (width ÷ 2) × water depth × 7.48
For example, a 24 ft round pool with 46 in. (3.83 ft) of water: 3.1416 × 12² × 3.83 × 7.48 ≈ 13,000 gallons, or about 49,000 liters.
What to do with your gallons
Your pool’s gallons drive every chemical dose, so this is the number to type into the chlorine calculator and the shock calculator. This page saves it in your browser so those tools fill it in for you.
The same number tells you what filling the pool will cost and how long it takes. The pool fill cost calculator compares tap water with a water truck, the guide to how long it takes to fill a pool covers hose time, and pool water delivery explains truckloads and prices.
For square footage, solar cover sizing or heater sizing, the pool surface area calculator works from the same measurements.
Closing the pool for the season? The guide to winterizing an above ground pool uses your gallons for the shock dose.
Assumptions and limitations
- Assumes the water sits 6 in. below the top of the wall unless you enter your own depth. Your pool's fill line may differ.
- Oval pools are treated as ellipses. Ovals with straight sides and rounded ends hold a little more than the chart shows.
- Assumes a flat floor. A sand cove or a dug-out center changes the real volume slightly.
Common questions
How many gallons are in a 24 ft round above ground pool?
About 13,000 gallons with a 52 in. wall filled to 46 in. of water. With a 48 in. wall it's about 11,800 gallons, and with a 54 in. wall about 13,500 gallons.
How many gallons are in an 18 ft round pool?
About 7,300 gallons with a 52 in. wall (46 in. of water), 6,700 gallons with a 48 in. wall and 7,600 gallons with a 54 in. wall.
How many gallons are in a 15 ft round pool?
About 5,100 gallons with a 52 in. wall (46 in. of water), 4,600 gallons with a 48 in. wall and 5,300 gallons with a 54 in. wall.
Why use the water depth instead of the wall height?
Above-ground pools aren't filled to the brim. The water usually sits about 6 in. below the top so the skimmer can work and rain doesn't spill over. Using the full wall height would overstate the gallons by about 13%.
Sources and methodology references
- How deep are above ground pools?, Royal Swimming PoolsDescribes the water level as about six inches below the top of the pool wall.
- NIST Special Publication 811: Guide for the Use of the International System of Units, National Institute of Standards and Technology1 ft³ = 7.4805 US gallons; 1 gallon = 3.7854 liters.
Results calculated from your inputs for homeowners, not professional advice. See how our calculators work. Published October 18, 2026.
Spotted a wrong result or an outdated source? Report a problem with this calculator.
Related tools
- Pool volume calculatorA pool gallons calculator and pool size calculator in one: pick your shape, enter a few tape-measure readings and see how many gallons, liters and cubic meters your pool holds.
- Chlorine calculatorSee how much chlorine to add to reach the right free chlorine level for your pool's stabilizer, in ounces, gallons or pounds of the product you actually have.
- Pool fill cost calculatorWork out what filling or topping up your pool will cost from the tap or by delivery truck, and how long a garden hose will take.
- Pool closing plannerAnswer a few questions and get a printable closing checklist with your shock and balancing doses already calculated.
Related guides
- How to Winterize an Above Ground Pool, Step by StepHow to winterize an above ground pool: when to close, how far to lower the water, what to do with the pump and hoses, and how to use an air pillow.Read the guide (7 min)
- How Long Does It Take to Fill a Pool? Hose Times by Pool SizeHow long it takes to fill a pool depends on gallons and your hose's flow. Measure your flow with a bucket, then use the table to see hours for your pool size.Read the guide (5 min)
- Pool Water Delivery Cost: What a Water Truck Charges to Fill a PoolPool water delivery usually costs about $30 to $100 per 1,000 gallons. See how many truckloads your pool needs, what drives the price and what to ask a hauler.Read the guide (5 min)
- Filling a Pool With Well Water: Test, Treat and Fill Without StainsCan you fill a pool with well water? Usually, yes. Test it for metals and hardness first, fill in stages so the well keeps up, and treat before adding chlorine.Read the guide (6 min)