Pool Volume Calculator
Calculate your swimming pool's volume in gallons and liters. Enter length, width and average depth for an instant, accurate result with the formula shown.
Updated 2026-06-14 · Free · No sign-up · Runs privately in your browser
Show the formula & steps
How the Pool Volume Calculator Works
This calculator finds how much water your swimming pool holds, in both US gallons and liters. Enter the pool’s length, width, and average depth in feet, and it instantly returns the volume.
The Formula
For a rectangular pool:
Volume (ft³) = length × width × average depth Gallons = Volume (ft³) × 7.48052
There are 7.48052 US gallons in one cubic foot of water. To convert gallons to liters, multiply by 3.785.
Worked Example
For a pool that is 32 ft long, 16 ft wide, with a 5 ft average depth:
- Volume = 32 × 16 × 5 = 2,560 ft³
- Gallons = 2,560 × 7.48052 = ≈ 19,150 US gallons
- Liters = 19,150 × 3.785 = ≈ 72,500 liters
Finding Your Average Depth
If your pool has a shallow and a deep end, use the average depth:
Average depth = (shallow depth + deep depth) ÷ 2
For a pool that is 3 ft at the shallow end and 7 ft at the deep end, the average depth is (3 + 7) ÷ 2 = 5 ft.
Why Pool Volume Matters
Knowing your exact pool volume lets you:
- Dose chemicals correctly — chlorine, salt, shock and algaecide are all added per a set number of gallons.
- Size equipment — pumps and heaters are rated by the volume they can turn over.
- Estimate fill time and cost — combine volume with your hose flow rate and water price.
| Pool size (L × W × avg depth) | Approx. gallons |
|---|---|
| 24 × 12 × 4 ft | ≈ 8,620 |
| 32 × 16 × 5 ft | ≈ 19,150 |
| 40 × 20 × 5.5 ft | ≈ 32,900 |
Frequently asked questions
How do I calculate the volume of my pool in gallons?+
Multiply length × width × average depth (all in feet) to get cubic feet, then multiply by 7.48052 to convert to US gallons. For example, a 32 × 16 ft pool with a 5 ft average depth holds 32 × 16 × 5 × 7.48052 ≈ 19,150 gallons.
What is the average depth of a pool?+
Average depth is the shallow-end depth plus the deep-end depth, divided by 2. For a pool that is 3 ft at the shallow end and 7 ft at the deep end, the average depth is (3 + 7) ÷ 2 = 5 ft. Use this average in the volume formula.
How many gallons is a 32x16 pool?+
A 32 ft × 16 ft pool with an average depth of 5 ft holds about 19,150 US gallons (72,500 liters). Adjust the average depth for your pool to get an exact figure.
Why do I need to know my pool's volume?+
Pool volume determines how much chlorine, salt, shock and other chemicals to add, how to size a pump and heater, and how long it takes to fill. Dosing chemicals by the correct volume keeps water safe and balanced.
How do I calculate volume for a round pool?+
For a round pool, volume in gallons = π × radius² × average depth × 7.48052, where radius is half the diameter (all in feet). This calculator covers rectangular pools; for round pools, use the radius-squared version of the formula.