Pool Volume Calculator
Calculate how many gallons or litres of water your pool holds. Select your pool shape and enter the dimensions below.
Unit:
Your Pool Volume
Gallons
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US Gallons
Litres
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Litres
How to Calculate Pool Volume
Knowing your pool's water volume is essential for proper chemical treatment, heating calculations, and pump sizing. Below are the formulas used for each pool shape.
Rectangular Pool
The simplest calculation — multiply length, width, and average depth:
Volume = Length × Width × Average Depth × 7.48 gallons/ft³ Oval Pool
Similar to a rectangle, but multiplied by π/4 (0.7854) to account for the elliptical shape:
Volume = Length × Width × Average Depth × 0.7854 × 7.48 gallons/ft³ Round Pool
Uses the standard circle area formula with the pool's diameter:
Volume = π × (Diameter ÷ 2)² × Average Depth × 7.48 gallons/ft³ Kidney-Shaped Pool
Adds the maximum and minimum widths together, multiplied by 0.45 to approximate the kidney curve:
Volume = Length × (Max Width + Min Width) × Avg Depth × 0.45 × 7.48 gallons/ft³ Tips for Accurate Measurements
- Measure at the water line, not the top of the pool wall.
- For average depth, add the shallow end depth to the deep end depth and divide by two.
- If your pool has a variable bottom, take multiple depth readings and average them.
- When in doubt, round up slightly — it's better to slightly over-treat than under-treat your pool water.