How Many Gallons Is a 16x32 Pool?
A 16 ft by 32 ft rectangular pool holds about 17,235 gallons of water (65,242 liters, or 65.2 m³) when it slopes from a 3 ft shallow end to a 6 ft deep end. That is 512 square feet of water surface at an average depth of 4.5 ft.
This is an estimate, not professional advice. Check the inputs against your own plans and local building code before you build or order. See terms and disclaimer.
Every number for this 16x32 pool
| Pool volume | 17,235 gal |
| Metric | 65,242 L |
| Cubic meters | 65.2 m³ |
| Volume | 2,304 ft³ |
| Surface area | 512 ft² |
| Average depth | 4' 6" |
How the number is worked out
Surface area depends on shape: rectangle = L × W, round = π × r², oval = π ÷ 4 × L × WAverage depth (ft) = (Shallow + Deep) ÷ 2Volume (ft³) = Surface area × Average depthGallons = Volume(ft³) × 7.48 Liters = Volume(ft³) × 28.32- Surface area = 32 ft × 16 ft = 512 ft²
- Average depth = (3 ft + 6 ft) ÷ 2 = 4.5 ft
- Volume = 512 ft² × 4.5 ft = 2,304 ft³
- Gallons = 2,304 ft³ × 7.48 = 17,235 gallons
What this number assumes
The number above is the volume of the water, not of the shell. It assumes a flat-bottomed pool that slopes evenly from the shallow end to the deep end, which is how a standard rectangular in-ground pool is built, and it uses the average of the two depths rather than the deep end alone. Using the deep end alone is the most common way people overestimate a pool by thousands of gallons.
Depth is where the real variation lives. Two 16x32 pools with the same footprint can differ by more than 7,000 gallons depending on how deep the deep end goes, so the table below is worth more than the single headline number. If your pool has a spa step, a beach entry or a hopper bottom, treat this as the upper bound of the flat-bottom case and subtract the volume those features displace.
Why the volume matters: chlorine, shock, algaecide and salt are all dosed per 10,000 gallons, and a pump and filter are sized to turn the whole volume over in 8 to 10 hours. Getting the gallons wrong by 20 percent means every chemical dose is wrong by 20 percent for the life of the pool.
A 16x32 pool by deep-end depth
Shallow end held at 3 ft. Each row is the same 16x32 footprint with a different deep end, so you can read your own pool off the table instead of trusting a single default.
| Deep end | Pool volume (gal) | Cubic meters (m³) | Average depth (ft) | |
|---|---|---|---|---|
| 4 ft | 13,405 | 50.7 | 3' 6" | Use → |
| 5 ft | 15,320 | 58 | 4' | Use → |
| 6 ft (this page) | 17,235 | 65.2 | 4' 6" | Use → |
| 7 ft | 19,150 | 72.5 | 5' | Use → |
| 8 ft | 21,065 | 79.7 | 5' 6" | Use → |
Different numbers?
Open the Pool Volume Calculator with this 16x32 pool already loaded and change anything you like. It runs the same formula shown above.
Method & assumptions
Every pool volume comes down to one idea: the surface area of the water times its average depth. The shape only changes how the area is found. A rectangle is length times width. A round pool is pi times the radius squared, where the radius is half the diameter. An oval is pi divided by four times the long axis times the short axis, which is the area of an ellipse. Once you have the area in square feet and the average depth in feet, multiplying them gives the volume in cubic feet.
Most in-ground pools have a sloped floor, so we average the two ends: average depth equals the shallow depth plus the deep depth, divided by two. A pool that runs from 3 feet to 7 feet has a 5 foot average. For a flat-bottom above-ground pool, leave the deep end at zero and the shallow figure is used directly. The single most common mistake is measuring the wall height instead of the water depth, because pools are almost never filled to the very top, so always measure to the actual water line.
To convert cubic feet to US gallons we multiply by 7.48052, the exact figure from NIST, rather than the rounded 7.5 that quick estimates use, and by 28.3168 for liters. Knowing the gallons is not just trivia: every chemical dose, chlorine, shock, muriatic acid and salt, is calculated per gallon, and so is pump and heater sizing, so a volume that is off by a thousand gallons throws off your whole chemistry. For an odd or freeform shape, split the pool into rectangles and half-circles, run each piece here, and add the results. If you also need the deck or coping around the pool, our square footage calculator handles that, and the concrete slab calculator sizes a poured deck.
Sources and references
These references and structured source records support the method and material data used on this page.
- Gallon and cubic foot conversions (NIST Handbook 44)
- Ellipse area (Wikipedia)
- Swimming pool (Wikipedia)