How this calculator works
It multiplies length × width × average depth for the volume in cubic feet, then converts to gallons (one cubic foot holds about 7.48 gallons).
Worked example — a 32 ft × 16 ft pool, 5 ft average depth:
512 sq ft × 5 = 2,560 cubic feet × 7.48 = ≈19,150 gallons.
512 sq ft × 5 = 2,560 cubic feet × 7.48 = ≈19,150 gallons.
Use the average depth
For a pool with a shallow and deep end, average the two depths. Knowing the gallons is essential for dosing chlorine and other chemicals correctly.
Frequently asked questions
How do I calculate pool gallons?
Length × width × average depth × 7.48 for a rectangular pool.
Why does pool volume matter?
Every chemical dose — chlorine, shock, algaecide — is based on the number of gallons.