Pool calculator
Pool volume calculator
Get accurate gallons for any standard pool shape. Use it before any chlorine, acid, alkalinity, or stabilizer dose.
Estimated volume
Enter your pool dimensions to see volume.
How it works
For rectangular pools, volume is length × width × average depth × 7.48. Round pools use π × radius² × depth × 7.48. Oval and kidney shapes use standard surface area approximations.
Average depth is the simple average of your shallow and deep ends. This is the same method pool stores use to estimate volume before recommending a dose.
Common questions
- How do I measure my pool accurately?
- Measure length and width at the widest points, and depth at both ends, then average them. For round pools, measure diameter across the center.
- Why does Ally round down on volume?
- Slightly undershooting volume means slightly under dosing chemicals. That is much safer than over dosing chlorine or acid.
- Does this account for shallow and deep ends?
- Yes. Enter both depths and the calculator uses the average, which is the standard method for pool volume math.