Pool Volume Calculator Formula
Understand the math behind the pool volume calculator. Each variable explained with a worked example.
Formulas Used
Volume (gallons)
gallons = cubic_ft * 7.481Volume (liters)
liters = cubic_ft * 28.317Volume (cubic ft)
volume_cuft = cubic_ftVariables
| Variable | Description | Default |
|---|---|---|
length_ft | Pool Length(ft) | 30 |
width_ft | Pool Width(ft) | 15 |
avg_depth_ft | Average Depth(ft) | 5 |
cubic_ft | Derived value= length_ft * width_ft * avg_depth_ft | calculated |
How It Works
How to Calculate Pool Volume
For a rectangular pool, multiply length x width x average depth to get cubic feet, then convert to gallons.
Formula
Volume (cu ft) = Length x Width x Average Depth
Gallons = Cubic Feet x 7.481
For variable-depth pools, average the shallow and deep end depths.
Worked Example
A 30 ft x 15 ft pool with 5 ft average depth.
- 01Volume = 30 x 15 x 5 = 2,250 cubic feet
- 02Gallons = 2,250 x 7.481 = 16,832 gallons
- 03Liters = 2,250 x 28.317 = 63,713 liters
Frequently Asked Questions
Why do I need to know pool volume?
Pool volume is essential for properly dosing chemicals (chlorine, pH adjusters), calculating fill/drain time, and estimating water costs.
How do I find average depth?
Add the shallow end depth and deep end depth, then divide by 2. For example, (3 ft + 7 ft) / 2 = 5 ft average.
How much does it cost to fill a pool?
At $4 per 1,000 gallons (typical municipal rate), a 15,000-gallon pool costs about $60 to fill from a hose.
Ready to run the numbers?
Open Pool Volume Calculator