Swimming Pool Volume Calculator - Gallons & Liters
Calculate swimming pool volume for rectangular, circular, or oval pools, in gallons and liters, with average or sloped-depth support.
Volume
2,250 ft³
Gallons
16,831
63,713 litersHow to Calculate Swimming Pool Volume
Pool volume is calculated as surface area multiplied by average depth. This calculator supports rectangular pools (length × width), circular or oval pools (using diameter, or two diameters for an oval), and either a single average depth or a shallow-end/deep-end pair for a sloped pool bottom, which gets averaged automatically.
Example
A rectangular pool measuring 30×15 ft with a sloped bottom from 3 ft (shallow) to 8 ft (deep) has an average depth of (3 + 8) / 2 = 5.5 ft. Volume = 30 × 15 × 5.5 = 2,475 cubic feet, which converts to about 18,519 gallons.
Common Use Cases
- Determining how much water is needed to fill a new or drained pool.
- Calculating the correct dose of pool chemicals, which scales with total water volume.
- Estimating filling time or water costs for a pool of a given size.
FAQs
How do I measure an oval pool?
Enter the pool's longest length and its widest width — the calculator treats these as the two axes of an ellipse and computes the area accordingly, which is the standard approximation used for oval pool volume.
Why average the shallow and deep end depths?
For a pool with a sloped bottom, the average of the shallow and deep depths gives a close approximation of the true average depth across the entire pool, since the slope is typically close to linear between the two ends.
How many gallons are in a cubic foot of water?
1 cubic foot of water equals approximately 7.48 gallons — that's the standard conversion factor this calculator uses to turn your pool's volume in cubic feet into US gallons.