Find out how many gallons (or liters) your swimming pool holds — for any shape, with or without a sloped bottom. Free, instant, no email required.
Pool shape
Depth
Drag the orange handles to set where the slope starts and ends.
Measure the depth of your water, not the height of the wall. For pools with a slope, use Shallow + Deep so we average correctly.
Estimated volume
17,235gallons
≈ 65,242 liters
Servicing more than one pool? You don’t have to save — “Use in Chlorine Calculator” carries this volume over without storing anything.
W × (Ls·Ds + Lslope·((Ds+Dd)/2) + Ld·Dd) × 7.48 → 16 × (9.6·3.5 + 12.8·((3.5+5.5)/2) + 9.6·5.5) ft
7.48 = U.S. gallons in 1 cubic foot of water.
Four quick tips for getting the right numbers into the fields above.
Use a marked pole or weighted tape from the waterline straight down to the floor.
Enter both depths in the Depth section and we average them — or use Sloped sections for a section-accurate result.
Measure the widest points across the long axis and the short axis — that's what goes into Length and Width.
Mentally break it into rectangles and circles. Use Freeform mode and add each section separately — we sum them.
Approximate gallons for standard residential pool dimensions.
| Shape | Dimensions | Gallons |
|---|---|---|
| Rectangle | 10 × 20 × 5 ft | 7,480 |
| Rectangle | 12 × 24 × 5 ft | 10,771 |
| Rectangle | 14 × 28 × 5 ft | 14,661 |
| Rectangle | 16 × 32 × 5 ft | 19,149 |
| Rectangle | 16 × 32 × 6 ft | 22,979 |
| Rectangle | 20 × 40 × 5 ft | 29,922 |
| Round | 15 ft Ø × 4 ft | 5,288 |
| Round | 18 ft Ø × 4 ft | 7,615 |
| Round | 24 ft Ø × 4 ft | 13,540 |
| Round | 27 ft Ø × 4 ft | 17,137 |
| Oval | 15 × 30 × 4 ft | 10,579 |
| Oval | 18 × 33 × 4 ft | 13,961 |
Quick answers to the questions homeowners ask about pool volume.
A 16-by-32-foot rectangular pool holds roughly 19,150 gallons at an average depth of 5 feet, or about 23,000 gallons at 6 feet of average depth. Depth makes the biggest difference: every extra foot of average depth adds about 16 × 32 × 7.48 = 3,830 gallons.
If your pool has a sloped bottom, add the shallow-end depth and the deep-end depth, then divide by two. That gives you the average for a uniform slope. For pools with a flat shallow section, a sloped middle, and a flat deep end, the sloped-sections mode in this calculator handles the geometry more precisely — measure each section length and the two depths.
Most in-ground residential pools in the US hold between 15,000 and 30,000 gallons. A common 16 × 32 with a 3-foot to 8-foot slope lands around 21,000 gallons. Above-ground pools are smaller: a 24-foot round above-ground pool at 4 feet deep is about 13,500 gallons.
Spas and hot tubs are much smaller — most residential spas hold 300 to 1,000 gallons. The math is the same (cylinder or rectangular box), but spas often have a seat or step bench that takes up water space. Use the 'Spa has a seat / step bench' option in this calculator to subtract that bench from the footwell volume automatically.
Multiply gallons by 3.785 to get liters. So a 20,000-gallon pool is about 75,700 liters. This calculator displays both — just toggle "Gallons" or "Liters" at the top.
How much liquid chlorine, bleach, or shock to add to hit your target free chlorine.
Open toolDial in cyanuric acid and the ideal FC/CYA ratio so your chlorine actually works.
Open toolHow much salt to add to reach your salt-chlorine generator’s target level.
Open tool