Pool Volume Calculator
Work out how many gallons and liters your pool holds from its shape and dimensions.
We average the shallow and deep depths, then multiply by the surface area and 7.48 gallons per cubic foot. For a pool with one uniform depth, just enter the same number twice.
How it works
Every pool chemical dose is figured per so-many gallons, so knowing your volume is the first thing to nail down. Get it wrong and your chlorine, salt, and acid amounts all drift off with it.
The math is surface area times average depth times 7.48 — the number of gallons in a cubic foot. For a rectangle that's length times width; for a round pool it's pi times the radius squared; for an oval it's about 78.5% of the enclosing rectangle. We average your shallow and deep ends to handle a sloped floor.
A 30-by-15-foot rectangular pool that runs 3 feet in the shallow end and 7 feet in the deep end averages 5 feet deep and holds about 16,800 gallons. Enter the same depth twice if your pool has a flat bottom.
Frequently asked questions
How do I handle a sloped floor?
Enter the shallow-end and deep-end depths separately and the calculator averages them. That average depth is what a straight-sloped floor works out to for volume purposes.
What's the 7.48 number?
There are 7.48 US gallons in one cubic foot of water. Once you have the pool's volume in cubic feet, multiplying by 7.48 converts it straight to gallons.
Why is the oval smaller than a rectangle of the same size?
An oval only fills about 78.5% of the rectangle that would box it in, because the corners are rounded off. That's the pi-over-four factor built into the oval formula.