Question 1

How do I calculate how many gallons are in my pool?

Accepted Answer

Multiply length × width × average depth in feet to get cubic feet, then × 7.48 for US gallons. A 32 × 16 ft rectangle sloping from 3.5 to 8 ft (average 5.75 ft) holds 32 × 16 × 5.75 × 7.48 ≈ 22,000 gallons. Round pools use π × radius² × depth × 7.48 (or diameter² × depth × 5.9), ovals length × width × depth × 5.9, and kidney shapes (A + B) ÷ 2 × length × depth × 6.7, where A and B are the two widths.

Question 2

What is the average depth if the pool slopes?

Accepted Answer

For a steady slope from shallow to deep end, average the two: (3.5 + 8) ÷ 2 = 5.75 ft. If the deep end is a small hopper rather than a long slope, the true average is closer to the shallow depth — measure depth at several points along the length and average them, or split the pool into sections and add the volumes.

Question 3

How long does it take to fill a pool with a garden hose?

Accepted Answer

A typical ⅝-inch hose delivers 8–10 gallons a minute, so a 22,000-gallon pool takes 37–46 hours — about two days of continuous filling. Time a 5-gallon bucket to get your real flow rate: 30 seconds to fill means 10 gal/min. Water delivery trucks bring 6,000–9,000 gallons per load if you would rather not wait.

Question 4

How much does it cost to fill a pool?

Accepted Answer

At a typical US municipal rate of $4–8 per 1,000 gallons, 22,000 gallons costs about $90–180, plus any sewer charge (some utilities credit pool fills — ask). Trucked water runs $300–800 per 6,000–9,000 gallon load. Once filled, evaporation and splash-out typically replace 25–50 % of the volume over a season.

Question 5

Why does pool volume matter for chemicals?

Accepted Answer

Every dose is per 10,000 gallons: 1 lb of calcium hypochlorite shock raises free chlorine about 10 ppm, 12–16 oz of muriatic acid lowers pH by roughly 0.2, and 1.5 lb of baking soda raises alkalinity 10 ppm. Underestimating volume means under-dosing and cloudy water; overestimating wastes chemicals and can bleach liners. Use the calculator’s gallons on every product label.

Pool	Size	Gallons
Above-ground round	15 ft × 48 in	4,900
Above-ground round	18 ft × 52 in	7,600
Above-ground round	24 ft × 52 in	13,500
Above-ground oval	15 × 30 ft × 52 in	10,200
In-ground rectangle	12 × 24 ft, 3–6 ft	9,700
In-ground rectangle	16 × 32 ft, 3.5–8 ft	22,000
In-ground rectangle	20 × 40 ft, 4–8 ft	35,900
Lap pool	10 × 50 ft, 4 ft	15,000
Hot tub	7 ft round, 3 ft	400

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Typical pool sizes in gallons

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