Pool Volume Calculator
Enter the shape and the depths you measured. The fields start with an example rectangle you should replace.
Result: volume
Average depth is 4.5 feet: (3 + 6) / 2.
Gallons = 15 × 30 × 4.5 × 7.48.
Sample geometry is not a survey of pools. A kidney-shape factor is not verified, so that shape is not offered.
How Many Gallons Is Your Pool?
Multiply length by width by average depth, then by 7.48, for a rectangle. Average depth is the shallow end plus the deep end, divided by 2.
Rectangle gallons = length × width × average depth × 7.48
Circle gallons = 3.14159 × radius × radius × average depth × 7.48
Oval gallons = 3.14159 / 4 × length × width × average depth × 7.48
Example rectangle: 15 feet by 30 feet, shallow 3 feet and deep 6 feet, is 15,147 gal. Standard conversion (also used in a CDC MAHC Annex worked example).
A circle can also be estimated as diameter squared times depth times 5.875. The result box uses the pi formula, with pi at 3.14159.
Pool Volume Calculator Results by Shape
These rows are sample dimensions, not a survey of pools. Replace them with your own measurements.
| Sample | Average depth | Gallons |
|---|---|---|
| Rectangle 15 ft by 30 ft, ends 3 ft and 6 ft | 4.5 ft | 15,147 gal |
| Rectangle 12 ft by 24 ft, both ends 4 ft | 4 ft | 8,617 gal |
| Circle, diameter 18 ft, depth 4 ft | 4 ft | 7,614 gal |
| Oval 16 ft by 32 ft, depth 4 ft | 4 ft | 12,032 gal |
Common Mistakes With the Pool Volume Calculator
- Using only the deep end. Average the shallow end and the deep end first.
- Treating a round pool as a rectangle. Switch the shape to circle and enter the diameter.
- Looking for a kidney factor. That factor is not verified, so this page does not offer the shape.
Use This Volume in Other Pool Calculators
Salt, chlorine, and shock all start from gallons.
Pool Volume Calculator FAQ
How many gallons is a 15 by 30 foot pool at an average depth of 4.5 feet?
15,147 gallons. That is length times width times average depth times 7.48.
How do you get average depth?
Add the shallow end and the deep end, then divide by 2. A pool that is 3 feet and 6 feet averages 4.5 feet.
Does this page use a kidney-shape factor?
No. An irregular-shape factor is not verified, so the calculator does not offer that shape.