A 15×48 above ground pool looks like one fixed size on the box, yet the water figure swings by hundreds of gallons depending on which model sits in your yard and how high you fill it. That gap isn’t a typo — it’s the fill line, the frame shape, and how the manufacturer measures usable water. Getting the number right matters before the first chemical dose goes in, because pool pumps and sanitizer charts are sized to the gallons actually in the water, not the frame printed on the carton.
The section below breaks down the real figures, then shows why 48 inches almost never means full-to-the-top.
What Decides the Water Volume In a 15-Foot Pool?
The deciding factor is the fill percentage the manufacturer uses, not the pool’s outer dimensions.
Above-ground pools are designed to sit below the top rail. That’s why two pools that both read “15ft x 48in” carry different gallon ratings: the Easy Set inflates to a rounded top ring and tops out lower, while the Prism Frame is a rigid steel structure that supports a fuller fill.
Use the manufacturer’s number for your exact model for dosing and pump sizing.
Verified Gallon Capacities for Common 15×48 Models
The table below lists what the manufacturer states for each model.
| Intex Model | Stated Water Capacity | Fill Level |
|---|---|---|
| Easy Set 15′ x 48″ | 3,736 gallons | 80% |
| Prism Frame 15′ x 48″ | 4,440 gallons | 90% |
| Metal Frame 15′ x 48″ | Not stated on product page | — |
| Generic 15 ft round, 48 in depth | About 5,288 gallons | 100% (theoretical) |
If you’re pricing out a setup and want a pool that holds a bigger swim session without a full rebuild, our tested 15 x 48 above ground pool roundup compares frame styles side by side.
Why “15×48” Doesn’t Tell You the Gallons
The label describes the frame, not the water.
Two things trip people up most often:
- Treating 48 inches as the water depth. The wall is 48 inches tall, but the water line sits below the top rail.
- Measuring the outer frame. The 15-foot figure is the outer diameter. The water-holding footprint is slightly inside that, so volume calculated from the outer edge runs high.
The Metal Frame 15′ x 48″ sits between the other two in rigidity, and Intex’s Metal Frame product page doesn’t publish a gallon figure, so you’d confirm the capacity on the carton or in the manual that ships with that specific model rather than assume it matches the Prism Frame.
References & Sources
- Intex. “15ft x 48in Metal Frame Pool Set.” Product page for the third frame style; no gallon figure published.