How many gallons in a round pool?

Find your brand and size in the chart for the manufacturer's real figure — usually a few thousand to over 12,000 gallons. If your pool isn't listed, measure the diameter across the water and the depth from the floor to the water line (not the wall), and the calculator computes it.

How many gallons in a 24 ft round pool?

An Intex 24-foot by 52-inch pool holds 12,481 gallons (the manufacturer's figure). Same nominal size from Coleman holds 12,772 — different liner, different fill convention.

Why is my pool's capacity less than the size suggests?

Because you don't fill to the rim. A 52-inch pool holds water to about 45 inches, around the skimmer mouth. That's about 15 percent below what a full 52-inch cylinder would hold — the manufacturer's published gallons already accounts for the real water line.

Do two pools of the same size hold the same water?

No. Same nominal size from different brands can differ by a few hundred gallons. 18×48: Intex 6,423 vs Coleman 6,092 — about 331 apart. Reasons: liner thickness, fill convention, wall-pad compression. The brand-specific manufacturer figure is the trusted one.

How do I measure my round pool's gallons?

Diameter across the water surface, then depth from the floor to the water line (not the wall height — that's the classic mistake). The calculator multiplies them through the cylinder formula. Because a round above-ground pool is uniform-depth, the math is simple and accurate.

What's the most common mistake?

Measuring to the rim instead of the water line. It inflates the gallons by about 20 percent and your chemical doses with them. The calculator's default Measure-It mode asks for wall height and freeboard separately, then subtracts — so the mistake can't happen by accident.

My pool isn't a standard brand — now what?

Use the Measure-It mode. Diameter across the water + water depth (not wall height), and the calculator handles it. The result is labeled an estimate — your numbers vs the manufacturer's measured one — but for a round pool the cylinder math is genuinely simple.

I have an in-ground or oval pool — is this the right tool?

No. This page is round above-ground specific. For ovals, kidneys, rectangles, L-shapes, or in-ground pools with a sloped deep end, use the general pool volume calculator — it handles seven pool shapes including the segmented diving-pool method.

Round Pool Gallons

Manufacturer-published water capacity for Intex, Bestway, and Coleman round above-ground pools. Sourced chart, not a formula — because a 52″ pool holds water to ~45″ and the same nominal size differs by brand.

Hook

Your pool holds less than the number on the box.

If you own a round above-ground pool — an Intex, a Bestway, a Coleman — the gallons figure you need isn't the one you'd get by multiplying it out as a full cylinder. A “24-foot by 52-inch” pool doesn't hold water to 52 inches; it holds it to about 45, because you never fill to the rim.

The real number is roughly fifteen percent below the full-cylinder math — and it even differs between brands of the very same nominal size. So the honest answer comes from the manufacturer's spec, not a formula.

Promise

This page gives you the real, manufacturer-published water capacity for common round above-ground pools — Intex, Bestway, and Coleman, by diameter and wall height — in a chart you can scan for your exact model. If your pool isn't listed, or you've measured it yourself, the calculator works it out from your actual water depth (not the wall height — that's the trick most people miss). Every charted number is from the maker's own spec, not computed. For in-ground or oddly-shaped pools, the general volume calculator is the better tool.

Here's the deal: a round pool's gallons is just the water cylinder — diameter and how deep the water actually sits. The catch is “how deep the water actually sits,” which is several inches below the wall, so the nominal size overstates it. We give you the manufacturer's measured number for your model, and if you'd rather compute, we make sure you measure to the waterline, not the top rail.

Two ways in

Pick your pool from the brand+size dropdown and you get the manufacturer's figure (exact). Or measure your own diameter and water depth (not wall height — see below) and the calculator computes it via the shipped volume engine. For non-round shapes, the general volume calculator is the right tool.

Two ways in: pick your pool from the verified chart, or measure your own. Either path lands on the real water-cylinder gallons, not the inflated full-cylinder nominal.

The calculator

Mode A is the primary path — pick a brand and size for the sourced gallons. Mode B handles off-chart pools via your measurements; the default two-step depth input prevents the classic rim-measurement error by construction.

For other pool shapes — oval, kidney, rectangular, in-ground with a deep end — use the general pool volume calculator. This page is the round above-ground specific lookup.

Find your pool in the chart

Start here: if you own a common round above-ground pool, your gallons are already known — the manufacturer measured and published them. The chart below lists the real water capacity for Intex, Bestway, and Coleman round pools by diameter and wall height.

Find your size, read your gallons. These aren't calculated from a formula; they're the figures each maker publishes for that exact model, which is why they're the number to trust for dosing chemicals or estimating a fill.

Ten representative sizes across three brands. Every figure here is the manufacturer's own measured water capacity — not a computed π·r²·h estimate, which would systematically overshoot.

Brand	Diameter	Wall height	Published gallons	Basis	Source
Intex	10 ft	30 in	1,185	90% of cylinder	intexcorp.com
Intex	18 ft	48 in	6,423	90% of cylinder	intexcorp.com
Intex	18 ft	52 in	6,981	actual water depth	intexcorp.com
Intex	24 ft	52 in	12,481	actual water depth	intexcorp.com
Bestway	10 ft	30 in	1,236	90% of cylinder	bestwayusa / Walmart
Bestway	12 ft	30 in	1,710	90% of cylinder	Walmart
Bestway	14 ft	33 in	2,700	as published	bestwayusa / Amazon
Bestway	15 ft	48 in	4,231	90% of cylinder	bestwayusa.com
Bestway	16 ft	48 in	5,145	90% of cylinder	bestwayusa.com / Menards
Bestway	20 ft	48 in	8,060	as published	Menards
Bestway	20 ft	52 in	8,781	90% of cylinder	Lowes
Coleman	16 ft	42 in	4,491	as published	Walmart
Coleman	18 ft	48 in	6,092	90% of cylinder	Walmart
Coleman	22 ft	52 in	10,668	90% of cylinder	Walmart
Coleman	24 ft	52 in	12,772	as published	Walmart

Sourced from manufacturer specifications (intexcorp.com, bestwayusa.com) and major US retailer product pages (Walmart, Lowes, Menards, Amazon). Released CC BY 4.0. If your size isn't in the chart, the calculator above handles it via your measured dimensions.

Why your pool holds less than the math says

Here's what trips people up. A pool sold as “24 foot by 52 inch” sounds like it should hold a 52-inch-deep cylinder of water — but it doesn't, because you never fill to the very top. The water line sits several inches below the rim, around the skimmer opening.

Intex, for its 52-inch pools, actually rates the water depth at about 45 inches. So if you multiply it out as a full 52-inch cylinder, you'll overshoot the real capacity by roughly fifteen percent— and over-dose your chemicals to match. The manufacturer's published number already accounts for the real water line. That's why the chart beats the formula.

The water line sits several inches below the rim — about seven on a 52″ pool. Treating the wall height as water depth overstates capacity by roughly 15 percent and over-doses every chemical to match.

Two fill conventions in published data: many 48-inch pools are rated “at 90%” (water at ~43 in); 52-inch pools are typically rated at actual water depth (~44–45 in, about 85% of the cylinder). Applying a flat “×90%” rule to all sizes is wrong for the 52-inch pools — use the sourced per-model figure instead.

Why two same-size pools hold different amounts

Stranger still: two pools with the identical size on the box can hold different amounts of water. An 18-foot-by-48-inch Intex holds about 6,423 gallons; the same nominal size from Coleman holds about 6,092 — a few hundred gallons apart, despite reading as the exact same pool.

The reasons are the liner thickness, the precise fill line each brand recommends, and small differences in the actual water-cylinder diameter once the liner and wall pad are in. This is exactly why a generic “round pool calculator” that just multiplies your dimensions can't give you the right answer — and why we use each maker's own measured figure instead.

Two pools sold as the same size — Intex 18-ft × 48-in versus Coleman 18-ft × 48-in — hold roughly 331 different gallons. Liner thickness, fill convention, and wall-pad compression vary by brand. The manufacturer's number captures that; a formula can't.

Measuring your own pool (if it's not in the chart)

If your pool isn't a charted model — an off-brand, an older pool, or a custom round — you can measure it, with one rule: measure the water, not the wall.

Take the diameter across the water surface, then measure how deep the water actually sits (not the height of the wall — the distance from the floor to the water line). Drop those into the calculator and it works out the gallons. Because a round above-ground pool is a true uniform cylinder, the math is simple and accurate — as long as that depth is the real water depth, not the rim.

Two simple measurements: diameter across the water surface, depth from the floor up to the water line. Measuring to the rim instead of the water inflates the answer by ~20 percent — the most common mistake.

The calculator's default Measure-It mode asks for wall height and the freeboard (how far below the rim the water sits), then subtracts — that two-step input means you can't accidentally enter wall height as water depth and inflate the answer by ~20% (see the next section's E7).

Where the numbers come from

Five steps from sourced chart → real gallons, with the compute-it fallback honest about being an estimate.

Step 1 · the chart is SOURCED, not computed
Every figure in the T1 stock-size chart comes from the manufacturer's own product spec page (intexcorp.com, bestwayusa.com) or a major US retailer's listing (Walmart, Lowes, Menards, Amazon) — never derived from π·r²·h. We render those literal integers; we don't recompute them. That's the page's integrity gate: if a chart row drifts to a formula output, the page reverts to a generic round-pool calculator and should redirect to the volume calculator instead.
Step 2 · fill-level convention (nominal ≠ water depth)
A “52-inch wall” pool holds water to about 45 inches — Intex says so explicitly. For our standard 24×52 Intex, π·r² at 52″ would give ~14,664 gal, but the published figure is 12,481 gal — a ~14.9% overstatementif you used the wall. Two conventions appear in published data: 48-inch pools at “90%” (water at ~43″); 52-inch pools at actual ~44–45″ (~85% of cylinder). A flat “×90%” rule is wrong for the 52″ pools — use the per-model figure.
Step 3 · cross-brand variance (the prize)
Same nominal 18×48: Intex publishes 6,423 gal; Coleman publishes 6,092 gal. That's a 331 gallon gap EXACT — same size on the box, different actual capacity. It comes from liner thickness, fill convention, and wall-pad compression. A formula can't produce that; the chart can.
Step 4 · the compute path (Mode B) reuses the volume engine
When your pool isn't in the chart, the calculator computes from your measured diameter and water depth via roundPoolGallons(d, h) — a thin wrapper in lib/volume/calculate.ts that composes the existing areaRound() formula and the NIST-exact GAL_PER_FT3 constant. No new cylinder math; cross-cluster reuse like the rest of the engine architecture.
Step 5 · the rim-error wedge (two-step input by construction)
The classic mistake: entering wall height as water depth. On a 15-ft pool, that turns ~4,406 real gallons into ~5,288 reported — 20% overstatement, and a 20% over-dose on every chemical. The Measure-It mode defaults to a TWO-STEP input (wall height + freeboard, subtract) so the error can't happen by accident. The advanced “I know my water depth” toggle exposes the direct input — and softly warns if the value looks like a wall height (48, 52 in).

Eight worked examples

Mode A examples render the SOURCED gallons from the chart (exact). Mode B examples run through the same roundPoolGallons engine the calculator uses (estimate, labeled).

E1 — 24 ft round pool gallons (the flagship, Mode A)

Intex 24 ft × 52 in → 12,481 gallons (manufacturer-published).

Takeaway:The most common big round pool — and the real figure is the maker's 12,481, not the ~14,664you'd get treating it as a full 52-inch cylinder.

E2 — The fill-level wedge (E1 continued)

Full-cylinder π·r²·h at 52″ ≈ 14,664 gal; actual published = 12,481 → nominal overstates by 2,183 gal (~14.9%) because water sits at ~45″, not 52″.

Takeaway: Dose to the real 12,481, not the full-cylinder number, or you'll over-treat by 15%.

E3 — The cross-brand insight (the prize)

18 ft × 48 in: Intex 6,423 vs Coleman 6,092 gal — 331 gallon gap EXACT.

Takeaway: Same size on the box, ~331gallons apart — which is why the maker's figure beats a generic formula.

E4 — A small common pool (Mode A)

Bestway 12 ft × 30 in → 1,710 gallons (90% basis).

Takeaway: The popular starter size; the published number already reflects the real fill.

E5 — Mid-size (Mode A)

Bestway 16 ft × 48 in → 5,145 gallons.

Takeaway: A common family size; read it straight from the chart.

E6 — Measure-it (Mode B, water-depth correct)

An unlisted 15 ft round filled to 40 in of actual water depth → π·(7.5²)·(40/12)·7.48052 ≈ 4,406 gal (computed estimate).

Takeaway: Off-chart pools compute fine — as long as you used the 40-inch water depth, not the wall height.

E7 — The rim-measurement error (cautionary)

That same 15-ft pool measured to a 48-in WALL instead of 40-in water → ~5,288 gal — ~881 gal (20%) too high.

Takeaway:Measuring to the rim instead of the water line is the classic mistake; it inflates your gallons ~20% and your chemical doses with it. The calculator's default two-step input prevents this.

E8 — Metric (Mode B)

A 5 m round at 1.1 m water depth → π·(2.5²)·1.1·1000 L/m³ ≈ 21,598 L ≈ 5,706 gal.

Takeaway: Same cylinder math in metric — diameter and real water depth. Routes through the same shipped engine.

For ovals, kidneys, rectangles, in-ground with a slope, or any non-round shape: use the general pool volume calculator.

Reference tables

T1 · Stock-size chart (the sourced centerpiece)

SOURCED · 15 rows manufacturer-published. Rendered as the chart in the “Find your pool” section above. Released CC BY 4.0. Cite as: PoolSolver, 2026 — aggregated from intexcorp.com, bestwayusa.com, and major US retailer listings.

T2 · Nominal vs actual by size (the fill-level wedge)

ESTIMATE column · the full-cylinder math (treating wall as water depth, no freeboard) vs the manufacturer's published actual. The gap is how much you'd overshoot by measuring to the rim.

Brand	Size	Published actual	Nominal at wall (computed)	Gap	Overstatement
Intex	10×30	1,185	1,469	+284	+19.3%
Intex	18×48	6,423	7,614	+1,191	+15.6%
Intex	18×52	6,981	8,249	+1,268	+15.4%
Intex	24×52	12,481	14,664	+2,183	+14.9%
Bestway	10×30	1,236	1,469	+233	+15.8%
Bestway	12×30	1,710	2,115	+405	+19.2%
Bestway	14×33	2,700	3,167	+467	+14.7%
Bestway	15×48	4,231	5,288	+1,057	+20.0%
Bestway	16×48	5,145	6,016	+871	+14.5%
Bestway	20×48	8,060	9,400	+1,340	+14.3%
Bestway	20×52	8,781	10,184	+1,403	+13.8%
Coleman	16×42	4,491	5,264	+773	+14.7%
Coleman	18×48	6,092	7,614	+1,522	+20.0%
Coleman	22×52	10,668	12,322	+1,654	+13.4%
Coleman	24×52	12,772	14,664	+1,892	+12.9%

T3 · Gallons by diameter × water depth (the compute reference)

EXACT math (round-cylinder geometry) · for off-chart pools, look up your diameter row × your measured water-depth column. Computed via roundPoolGallons (the same engine the calculator uses).

Diameter \ water depth	24″	30″	36″	42″	45″
10 ft	1,175	1,469	1,763	2,056	2,203
12 ft	1,692	2,115	2,538	2,961	3,173
15 ft	2,644	3,305	3,966	4,627	4,957
18 ft	3,807	4,759	5,711	6,662	7,138
20 ft	4,700	5,875	7,050	8,225	8,813
22 ft	5,687	7,109	8,531	9,953	10,663
24 ft	6,768	8,460	10,152	11,844	12,690

Tables released CC BY 4.0. T1 is sourced (manufacturer/retailer specs); T2 column “Published actual” is sourced and the rest is computed; T3 is pure geometry.

Methodology & sources

The stock-size chart (T1) is manufacturer-sourced. Every figure comes from an Intex, Bestway, or Coleman product spec page (intexcorp.com, bestwayusa.com) or a major US retailer listing (Walmart, Lowes, Menards, Amazon). We render those literal integers as data; we do not recompute them from π·r²·h. This is the page's unique value: a generic round-pool calculator structurally cannot tell you that the same nominal 18×48 holds 6,423 gallons by Intex but 6,092 by Coleman — that 331-gallon spread comes from liner thickness and fill convention, captured in the published spec, not in any formula.

The fill-level convention— manufacturers publish at the actual water line, several inches below the rim. Intex explicitly states 45-inch water depth in their 52-inch wall pools. Many 48-inch pools are rated “at 90 percent” (water at ~43 in). A flat “multiply by 0.9” rule is wrong for 52-inch pools, whose published gallons reflect ~85 percent of the full cylinder. We cite the basis per row in T1 and surface the convention prominently in the result panel.

The compute path (Mode B) reuses the volume engine. The diameter + water-depth → gallons function is a thin wrapper in lib/volume/calculate.ts (roundPoolGallons) that composes the existing areaRound() and the NIST-exact GAL_PER_FT3 constant. No new cylinder math; same engine the pool volume calculator uses for its round-shape path.

The two-step depth input is by construction.Mode B defaults to asking wall height plus the freeboard (how far the water sits below the rim), then subtracts to get water depth — so the classic rim-measurement error (treating wall height as water depth, which inflates gallons by ~20 percent and over-doses every chemical) cannot happen by accident. The advanced “I know my water depth” toggle exposes the direct input for users who've already measured correctly; if they enter a value that matches a common wall height (48, 52 in), a soft warning prompts them to double-check.

Honesty boundary.Mode A results are sourced exact (manufacturer-published, cited per row). Mode B results are computed estimates (your measurements × the engine), labeled as such. Liner and wall-pad compression are noted qualitatively — the manufacturer's published gallons already bake in a small diameter reduction from those; we don't invent a separate correction.

Scope: round above-ground pools specifically. For non-round, in-ground, irregular, or non-standard shapes, the general pool volume calculator handles seven pool shapes including round; this page is the AGP-specific lookup. ONE URL; no per-size or per-brand variants — those are chart rows and calculator presets.

3rd spoke of the Pool Water & Filling cluster (after cost-to-fill and fill-time). The water hub's four-questions arc — “how big do the standard pools hold” — is answered here. Bidirectional bridge to the volume calculator: round-pool sends non-round shapes there; volume sends AGP-round users back here. Anti-doorway routing by construction.

Reference tables released under CC BY 4.0. T1 cite: aggregated from manufacturer specs (intexcorp.com, bestwayusa.com) and major US retailer listings.

Frequently asked questions

How many gallons in a round pool?: Find your brand and size in the chart for the manufacturer's real figure — usually a few thousand to over 12,000 gallons. If your pool isn't listed, measure the diameter across the water and the depth from the floor to the water line (not the wall), and the calculator computes it.
How many gallons in a 24 ft round pool?: An Intex 24-foot by 52-inch pool holds 12,481 gallons (the manufacturer's figure). Same nominal size from Coleman holds 12,772 — different liner, different fill convention.
Why is my pool's capacity less than the size suggests?: Because you don't fill to the rim. A 52-inch pool holds water to about 45 inches, around the skimmer mouth. That's about 15 percent below what a full 52-inch cylinder would hold— the manufacturer's published gallons already accounts for the real water line.
Do two pools of the same size hold the same water?: No. Same nominal size from different brands can differ by a few hundred gallons. 18×48: Intex 6,423 vs Coleman 6,092 — about 331 apart. Reasons: liner thickness, fill convention, wall-pad compression. The brand-specific manufacturer figure is the trusted one.
How do I measure my round pool's gallons?: Diameter across the water surface, then depth from the floor to the water line (not the wall height— that's the classic mistake). The calculator multiplies them through the cylinder formula. Because a round above-ground pool is uniform-depth, the math is simple and accurate.
What's the most common mistake?: Measuring to the rim instead of the water line. It inflates the gallons by about 20 percentand your chemical doses with them. The calculator's default Measure-It mode asks for wall height and freeboard separately, then subtracts — so the mistake can't happen by accident.
My pool isn't a standard brand — now what?: Use the Measure-It mode. Diameter across the water + water depth (not wall height), and the calculator handles it. The result is labeled an estimate — your numbers vs the manufacturer's measured one — but for a round pool the cylinder math is genuinely simple.
I have an in-ground or oval pool — is this the right tool?: No. This page is round above-ground specific. For ovals, kidneys, rectangles, L-shapes, or in-ground pools with a sloped deep end, use the general pool volume calculator — it handles seven pool shapes including the segmented diving-pool method.

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