Free tool
Pool Volume Calculator
Estimate your pool's volume in gallons or liters — the number every other dosing calculation starts with.
How to use this calculator
- 1Pick your pool's shape
Choose rectangle, round, oval, or kidney/freeform — each shape uses its own industry-standard formula.
- 2Enter your dimensions
Measure length, width (or diameter for round pools), and average depth in feet. Have a shallow and deep end? Add them together and divide by two.
- 3Read your estimate
Your pool's volume appears instantly in both gallons and liters.
- 4Use it in the other calculators
Copy the gallon figure into the Chlorine or pH calculator — every dosing formula starts with pool volume.
Frequently asked
Questions about pool volume
How accurate is this pool volume estimate?
This uses the same industry-standard formulas pool professionals use for quick estimates — accurate to within about 10-15% for most pools. Irregular or heavily stepped pools may vary more. If you need an exact number, check your pool's original builder specs or ask your installer.
What if my pool has a shallow end and a deep end?
Add the shallow and deep depths together and divide by two to get your average depth, then use that number. A pool with a 3ft shallow end and an 8ft deep end has an average depth of 5.5ft.
Why does pool shape matter for the formula?
Each shape uses a different multiplier because the formula approximates how much of the pool's footprint holds water at that average depth. A kidney or freeform pool, for example, uses a two-width approximation instead of a single width.
Why do I need to know my pool's volume?
Nearly every chemical dosing calculation — chlorine, pH, alkalinity, calcium hardness — starts with your pool's volume in gallons. Get this number right once, then reuse it in Skimmer's other calculators (or in the Skimmer app, which remembers it for you).