Pool Volume by Size — Complete Reference Table
A pool volume chart covering round, oval and rectangular pools at standard depths — every figure in US gallons and litres.
Most Searched Pool Sizes
Volumes at standard depth (5 ft avg for rectangular, 4 ft for round). Actual gallons vary with your water depth — see measurement guide.
How to Use This Pool Volume Size Chart
Use this pool size volume chart to find your pool's volume without calculating. Tables below show volumes at standard depths — 4 ft (48 in) and 4.33 ft (52 in) for above-ground pools, 5 ft and 5.5 ft average depth for inground pools. All figures use inner wall-to-wall measurements, not outer frame or box dimensions.
Water depth ≠ wall height. Always measure from the waterline to the pool floor. Wall height includes freeboard (the dry section above water), which overstates volume. For sloped pools: average depth = (shallow end + deep end) ÷ 2.
If your water depth differs from the table standards, enter your exact dimensions into the pool volume calculator for a precise result. Results available in gallons or litres. For shapes not covered here — kidney, L-shaped, freeform — see the pool volume calculator by shape.
Round Pool Volume by Size
Round pools are the most common above-ground pool shape. Volumes below cover 10 ft to 33 ft diameter at two standard wall depths.
Round Pool Volume at 4.0 ft (48 in) Depth
| Diameter | US Gallons | Litres |
|---|---|---|
| 10 ft | 2,356 | 8,919 |
| 12 ft | 3,384 | 12,810 |
| 14 ft | 4,605 | 17,427 |
| 15 ft | 5,288 | 20,016 |
| 16 ft | 6,028 | 22,824 |
| 18 ft | 7,614 | 28,823 |
| 21 ft | 10,362 | 39,225 |
| 24 ft | 13,536 | 51,241 |
| 27 ft | 17,142 | 64,902 |
| 30 ft | 21,168 | 80,122 |
| 33 ft | 25,626 | 97,003 |
Formula: D² × 4.0 × π/4 × 7.48052. Litres = US gal × 3.78541. Inner diameter used — not box size.
Round Pool Volume at 4.33 ft (52 in) Depth
| Diameter | US Gallons | Litres |
|---|---|---|
| 10 ft | 2,554 | 9,672 |
| 12 ft | 3,666 | 13,878 |
| 14 ft | 4,989 | 18,888 |
| 15 ft | 5,728 | 21,687 |
| 16 ft | 6,530 | 24,720 |
| 18 ft | 8,249 | 31,230 |
| 21 ft | 11,226 | 42,504 |
| 24 ft | 14,663 | 55,510 |
| 27 ft | 18,571 | 70,299 |
| 30 ft | 22,935 | 86,832 |
| 33 ft | 27,762 | 105,118 |
Formula: D² × 4.33 × π/4 × 7.48052. Litres = US gal × 3.78541.
If your round pool diameter is not listed, enter the inner diameter and water depth into the round pool volume calculator for an exact result in both units.
Oval Pool Volume by Size (Above-Ground)
Oval above-ground pools use the ellipse factor (π/4 = 0.7854) applied to length × width — not a simple rectangle formula.
| Pool Size | Depth | US Gallons | Litres |
|---|---|---|---|
| 10 × 16 ft | 4.0 ft | 3,770 | 14,272 |
| 12 × 20 ft | 4.0 ft | 5,640 | 21,350 |
| 12 × 24 ft | 4.0 ft | 6,768 | 25,625 |
| 15 × 24 ft | 4.0 ft | 8,460 | 32,027 |
| 15 × 30 ft | 4.0 ft | 10,575 | 40,032 |
| 18 × 33 ft | 4.0 ft | 13,876 | 52,519 |
Formula: L × W × 4.0 × π/4 × 7.48052. Litres = US gal × 3.78541. Inner wall measurements used.
For oval sizes not shown above, enter your inner length, width and water depth into the oval pool volume calculator for a precise result.
Rectangular Pool Volume by Size (Inground)
Rectangular inground pools use average depth — most slope from a shallow end of 3.5 ft to a deep end of 7–8 ft, giving a 5–5.5 ft average.
Rectangular Pool Volume at 5.0 ft Average Depth
| Pool Size | US Gallons | Litres |
|---|---|---|
| 10 × 20 ft | 7,481 | 28,320 |
| 12 × 24 ft | 10,772 | 40,782 |
| 14 × 28 ft | 14,664 | 55,510 |
| 15 × 30 ft | 16,830 | 63,726 |
| 16 × 32 ft | 19,175 | 72,593 |
| 18 × 36 ft | 24,261 | 91,852 |
| 20 × 40 ft | 29,922 | 113,299 |
| 25 × 50 ft | 46,753 | 177,031 |
Formula: L × W × 5.0 × 7.48052. Litres = US gal × 3.78541. Average depth used — measure shallow end + deep end ÷ 2.
Rectangular Pool Volume at 5.5 ft Average Depth
| Pool Size | US Gallons | Litres |
|---|---|---|
| 10 × 20 ft | 8,229 | 31,155 |
| 12 × 24 ft | 11,850 | 44,872 |
| 14 × 28 ft | 16,131 | 61,072 |
| 15 × 30 ft | 18,513 | 70,104 |
| 16 × 32 ft | 21,093 | 79,853 |
| 18 × 36 ft | 26,687 | 101,047 |
| 20 × 40 ft | 32,920 | 124,648 |
| 25 × 50 ft | 51,428 | 194,737 |
Formula: L × W × 5.5 × 7.48052. Litres = US gal × 3.78541.
For rectangular pools with a depth outside 5.0–5.5 ft, enter your exact average depth into the rectangular pool volume calculator for a result matched to your pool.
Size Not Listed? Get an Exact Result
Option 1 — Use the calculator. Enter your exact length, width and depth into the pool volume calculator for an instant result in gallons and litres. Shape-specific calculators are available for above-ground, round, oval, and rectangular pools.
Option 2 — Apply the formula. Rectangular: L × W × avg depth × 7.48052. Round: D² × depth × π/4 × 7.48052. Oval: L × W × depth × π/4 × 7.48052. All return US gallons — multiply by 3.78541 for litres. For worked examples and constant explanations, see pool volume formulas.
Frequently Asked Questions
How many gallons in a 16×32 ft pool?
A 16×32 ft rectangular inground pool holds 19,175 US gallons (72,593 litres) at 5.0 ft average depth, or 21,093 US gallons (79,853 litres) at 5.5 ft average depth. The formula is 16 × 32 × average depth × 7.48052. Average depth equals shallow end plus deep end divided by 2 — a pool with a 3.5 ft shallow end and a 6.5 ft deep end averages 5.0 ft. Multiply gallons by 3.78541 to convert to litres.
How many gallons in a 12×24 ft pool?
A 12×24 ft rectangular inground pool holds 10,772 US gallons (40,782 litres) at 5.0 ft average depth, or 11,850 US gallons (44,872 litres) at 5.5 ft average depth. The formula is 12 × 24 × average depth × 7.48052. Measure your shallow end and deep end, add both, and divide by 2 to find your average depth. If your average depth differs from 5.0 or 5.5 ft, enter exact dimensions into the pool volume calculator for a precise result.
How many gallons does an 18 ft round pool hold?
An 18 ft round pool holds 7,614 US gallons (28,823 litres) at 48 inches (4.0 ft) water depth, or 8,249 US gallons (31,230 litres) at 52 inches (4.33 ft) water depth. The formula is 18² × depth × π/4 × 7.48052. Use the inner wall-to-wall diameter — not the size printed on the box. The box dimension describes the outer frame, which is typically 4–8 inches wider than the actual water area.
How many gallons in a 24 ft round pool?
A 24 ft round pool holds 13,536 US gallons (51,241 litres) at 48 inches (4.0 ft) water depth, or 14,663 US gallons (55,510 litres) at 52 inches (4.33 ft) water depth. The formula is 24² × depth × π/4 × 7.48052. Measure the inner diameter from wall to wall across the centre of the pool at the waterline. The extra 4 inches of water at 52-inch depth adds 1,127 gallons (4,269 litres) over the 48-inch figure.
How many gallons does a 20×40 ft pool hold?
A 20×40 ft rectangular inground pool holds 29,922 US gallons (113,299 litres) at 5.0 ft average depth, or 32,920 US gallons (124,648 litres) at 5.5 ft average depth. The formula is 20 × 40 × average depth × 7.48052. This is a large residential pool — the 5.5 ft depth figure accounts for a typical 3.5 ft shallow end and 7.5 ft deep end. Multiply US gallons by 3.78541 for litres.
How do I use this table if my pool size is not listed?
Two options: use the calculator or apply the formula manually. Option 1: enter your exact length, width and depth into the pool volume calculator for an instant result in gallons and litres. Option 2: apply the formula yourself — for rectangular pools, multiply length × width × average depth × 7.48052 to get US gallons. For all shape formulas including round, oval, kidney and L-shaped, see pool volume formulas for all shapes.