Know exactly how many gallons your pool holds.
Enter your pool shape, dimensions and depth to see the volume in gallons, the average depth, how fast your pump turns the water over, and what it costs to fill.
Your pool
For a flat-bottom pool, set both depths the same.
Most utilities bill water per unit of 748 gallons (one hundred cubic feet).
What your volume tells you
Volume by shape at your dimensions
Same length, width and depth, three shapes
Chemical dosing at this volume
The numbers at a glance
Gallons at different average depths
Your current shape and length and width, held constant, at a range of average depths.
| Average depth | Cubic feet | Gallons | Turnover | Fill cost |
|---|
Pool volume, explained
How to Calculate Pool Volume
Pool volume depends on shape and average depth. For rectangular pools: Length x Width x Average Depth x 7.48 gallons per cubic foot. For circular pools: pi x radius squared x Average Depth x 7.48. Average depth is calculated as (shallow depth + deep depth) / 2 for pools with a gradual slope.
Why Pool Volume Matters
Knowing your pool volume is essential for proper chemical treatment, including chlorine, pH balancers, algaecide, and shock treatments. Incorrect dosing can lead to unsafe water or wasted chemicals. Volume is also needed for calculating pump sizing, heater BTU requirements, and water replacement costs.
Common questions
How many gallons are in a typical pool?
A typical residential pool holds 10,000 to 30,000 gallons. A small above-ground pool (15 feet round, 4 feet deep) holds about 5,300 gallons. A large in-ground pool (20x40 feet, 5 feet average depth) holds about 30,000 gallons.
What is 7.48 gallons per cubic foot?
One cubic foot of water equals 7.48 US gallons. This conversion factor is used to convert the pool volume from cubic feet to gallons, which is the standard unit for pool chemical dosing.
How do I measure average depth?
For a pool with a uniform slope, average depth = (shallow end + deep end) / 2. For pools with a hopper bottom or irregular shape, measure depth at several points and average them for a more accurate estimate.
Estimates for planning only. Actual volume varies with pool floor contours, hopper bottoms, steps and benches. Always confirm chemical doses against the product label and test your water before dosing.