pool volume calculator
Find out how many gallons or litres your pool holds, whether it’s rectangular, round or oval with a sloped floor, and how long it’ll take to fill.
fashion law journal · tools deskupdated 25 sep 2026US gallons & litres
Quick answer: for a rectangular pool, gallons = length × width × average depth (all in feet) × 7.48. For a round pool, gallons = diameter² × average depth × 5.9. A 16 × 32 ft pool averaging 4.5 ft deep holds about 17,200 gallons.
Same depth everywhere? Enter it in both depth boxes. An average garden hose delivers roughly 5 to 10 gallons a minute.
pool volume formulas
| shape | gallons (feet) | litres (metres) |
|---|---|---|
| Rectangle | L × W × avg depth × 7.48 | L × W × avg depth × 1,000 |
| Round | diameter² × avg depth × 5.9 | diameter² × avg depth × 785 |
| Oval | L × W × avg depth × 5.9 | L × W × avg depth × 785 |
Average depth = (shallow + deep) ÷ 2. For kidney or freeform pools, use the oval formula with the longest length and average width as a good estimate.
before you fill it
Many US cities and counties require a permit and a barrier (often a fence at least 4 ft high with a self-closing, self-latching gate) for pools deeper than 24 inches, including above-ground pools. Check your local rules and your homeowner’s insurance before filling. Some water utilities also offer a pool-fill credit on sewer charges if you call ahead.
pool volume questions
Why do I need to know my pool’s volume?
Chemical doses (chlorine, pH adjusters, shock) are given per gallon or litre. Guessing the volume leads to over- or under-treating, which wastes money and irritates skin and eyes.
How many gallons in a cubic foot?
About 7.48 US gallons. A cubic metre holds 1,000 litres (about 264 US gallons).
How long does it take to fill a pool with a hose?
Divide the gallons by your hose’s flow rate. A 15,000-gallon pool at 9 gallons a minute takes about 28 hours.
How many gallons is an above-ground pool?
A 24 ft round pool 4 ft deep (filled to about 3.6 ft) holds roughly 12,000 to 13,000 gallons.
Estimates only. Use your pool manufacturer’s specifications for exact figures. Not legal advice. More tools: cubic yard calculator · square footage calculator.