Pool Volume Calculator
Calculate swimming pool volume in gallons, liters, and cubic feet for rectangular, round, and oval pools. Includes fill time, heating BTU, and chemical dosing.
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ft
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Gallons
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Liters —
Cubic Feet —
Extended More scenarios, charts & detailed breakdown ▾
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Gallons
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Liters —
Avg Depth —
Professional Full parameters & maximum detail ▾
gal
GPM
°F
ppm
Fill Time
Fill Time —
Fill Time (mins) —
Heating
Heating BTU Required —
Chemicals & Cost
Chlorine Needed —
Water Fill Cost —
How to Use This Calculator
- Select your pool shape (rectangle, circle, or oval).
- Enter dimensions and average depth in feet.
- Results show volume in gallons, liters, and cubic feet.
Formula
Rectangle: L × W × D × 7.48 gallons
Circle: π × r² × D × 7.48 | Oval: π × (L/2) × (W/2) × D × 7.48
1 cu ft = 7.48052 gallons | 1 gallon = 3.78541 liters
Example
Example: 20 ft × 40 ft rectangle, 5 ft avg depth → 4,000 cu ft → 29,922 gallons = 113,276 liters.
Frequently Asked Questions
- For a rectangle: Length × Width × Average Depth × 7.48 = gallons. For a circle: 3.14 × Radius² × Average Depth × 7.48 = gallons.
- Add the shallow end depth and the deep end depth, then divide by 2. For example (3 ft + 8 ft) ÷ 2 = 5.5 ft average depth.
- Divide pool gallons by your fill rate in GPM. A standard garden hose delivers about 9–12 GPM. A 20,000-gallon pool at 10 GPM takes about 33 hours.
- To raise chlorine by 1 ppm in 10,000 gallons you need about 1.3 oz of granular chlorine. This calculator estimates dosing based on your pool volume.
- BTU required = Gallons × 8.34 × Temperature rise (°F). For a 20,000-gallon pool heated 10°F that is about 1.67 million BTU.