Pool Volume Calculator
Calculate swimming pool volume in cubic feet, US gallons, and liters. Free online pool size calculator for rectangular, oval, and circular pools with charts.
About This Calculator
The Pool Volume Calculator helps homeowners, pool installers, and service professionals determine the exact water volume of any swimming pool. Whether you are filling a new pool, calculating chemical dosages, or estimating water costs, knowing your pool's volume in cubic feet, US gallons, and liters is essential.
For rectangular and square pools, volume is calculated using the formula: Volume = length × width × average depth, where average depth = (shallow end depth + deep end depth) / 2. For oval and circular pools, the formula adjusts for the elliptical shape: Volume = (π × length × width / 4) × average depth. This method accounts for gradually sloping bottoms by treating the side profile as a trapezoid and converting it to an equivalent rectangle.
Regional Notes
United States: Pool volumes are most commonly measured in US gallons. The standard conversion factor is 7.48 gallons per cubic foot. Water utility rates vary by municipality, averaging $1.50 per 1,000 gallons.
United Kingdom: Pool volumes are typically measured in liters or cubic meters. The conversion is 28.32 liters per cubic foot. Water costs range from £2-3 per 1,000 liters depending on the water supplier.
India: Pool volumes are measured in liters or kiloliters. Water tanker delivery prices vary significantly by city, from ₹500-2,000 per 1,000 liters in metro areas. Many residential pools in India use rectangular designs with uniform depth.
Olympic-sized swimming pools measure 50 m × 25 m × 2 m (minimum depth), holding about 2.5 million liters or 660,000 US gallons. Use the calculator to compare your pool size against Olympic standards.
Frequently Asked Questions
How do I calculate how many gallons my pool holds?
Measure the length, width, and average depth of your pool in feet. For a rectangular pool, multiply length × width × average depth to get cubic feet, then multiply by 7.48 to convert to US gallons. For oval pools, multiply length × width × average depth × π/4, then multiply by 7.48.
What is the formula for pool volume calculation?
For a rectangular pool: Volume = length × width × average depth. For an oval or circular pool: Volume = (π × length × width / 4) × average depth. Average depth is calculated as (shallow end depth + deep end depth) / 2.
How much water does an Olympic swimming pool hold?
An Olympic-sized swimming pool holds approximately 2,500,000 liters (660,000 US gallons) of water. It measures 50 meters long, 25 meters wide, and has a minimum depth of 2 meters. The recommended depth is 3 meters.
How much does it cost to fill a swimming pool?
The cost to fill a pool depends on your local water rates and pool volume. In the US, water costs approximately $1.50 per 1,000 gallons. A typical 20,000-gallon pool would cost around $30 to fill. In the UK, water costs about £2-3 per 1,000 liters. In India, water tanker delivery costs vary by city.
Should I measure depth from the waterline or the pool floor?
Measure depth from where you want the waterline to be, typically a few inches below the pool rim. For accurate volume calculations, use the actual water depth rather than the structural depth of the pool.
How do I calculate pool volume if the bottom slopes gradually?
For pools with a gradual slope from shallow to deep end, use the average depth: (shallow end depth + deep end depth) / 2. This works because the trapezoidal side of the pool can be transformed into an equivalent rectangle with height equal to the average depth.
How much chlorine do I need for my pool?
After calculating your pool volume, a general guideline is 52-104 oz of liquid chlorine (1.5-3.1 liters) per 10,000 gallons of water for breakpoint chlorination. Always follow the manufacturer's instructions for your specific chlorine product.
What if my pool has an irregular shape?
For irregularly shaped pools, divide the pool into smaller rectangular or circular sections, calculate each section's volume separately, and add them together. The calculator assumes a uniform gradual depth change; for complex shapes, measure each section individually.