Your pool holds about
How pool volume is calculated
A cubic foot of water is 7.48 gallons. Multiply the surface area by the average depth, then by 7.48. For round and curved shapes, the factors below already include the geometry:
| Shape | Formula (feet → gallons) |
|---|---|
| Rectangle | length × width × average depth × 7.48 |
| Round | diameter × diameter × average depth × 5.9 |
| Oval | length × width × average depth × 5.9 |
| Kidney | (widest + narrowest end) × length × average depth × 3.38 |
Common above-ground pool sizes
Filled to the usual water level (about 6 inches below the top of the wall):
| Pool | 48" wall | 52" wall | 54" wall |
|---|
Why your volume matters
Every dose on this site scales with volume. If you overestimate by 20%, you add 20% too much chlorine or acid every single time. Measuring once, carefully, saves money and keeps your water stable. Once saved, every calculator on PoolDose fills in your volume automatically.
Sources and methodology
Last reviewed: November 2026. Doses are calculated from the chemistry of each product (molecular weights and available chlorine) and cross-checked against manufacturer and industry dosing charts. Recommended ranges follow CDC guidance for home pools and hot tubs.
Frequently asked questions
How many gallons is a 15 ft round above ground pool?
A 15 ft round pool filled to 4 ft deep holds about 5,300 gallons (15 × 15 × 4 × 5.9). With 48-inch walls, the water is usually filled to about 42 inches, which gives roughly 4,600 gallons.
How do I measure the depth of a pool with a slope?
Measure the shallow end and the deep end and use the average. If the deep part is only a small area (like a diving well), use the depth where most of the pool is.
How accurate is a pool volume calculation?
Usually within 5–10%, which is fine for dosing. If your doses always over- or under-shoot, adjust your saved volume slightly.