Pool volume calculator
Every chemical dose scales with your pool’s volume, so getting the gallons right matters most. Enter your pool’s shape and dimensions to estimate it.
How to calculate pool volume
Volume is surface area times average depth, converted to gallons. For a rectangle it is length × width × average depth × 7.48. Round pools use about 5.9 and oval pools about 6.7 instead of 7.48, because their surface is smaller than the rectangle around them. Average depth is your shallow and deep depths added together and divided by two.
Why volume matters so much
Every dose in the chemistry calculators scales directly with volume. A 20% error in gallons is a 20% error in every chemical you add, so measure carefully and round honestly. If your pool is an unusual shape, split it into sections, estimate each, and add them up.
Measuring tips
Measure length and width at the water line, not the deck. For average depth, take the shallow-end and deep-end depths and average them. For a round pool, the diameter is the distance straight across the middle.
Frequently asked questions
How do I find my pool’s volume in gallons?
Multiply length × width × average depth (in feet) by 7.48 for a rectangle. Round pools use about 5.9 and ovals about 6.7. This calculator does it for you in gallons and litres.
What is the average depth?
Add your shallow-end depth and deep-end depth and divide by two. A pool that is 3 ft shallow and 7 ft deep has an average depth of 5 ft.
How accurate is this estimate?
It is close for standard shapes. Irregular or kidney-shaped pools vary, so treat the result as an estimate, start chemical doses conservatively, and re-test.
Related calculators & guides
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