Free pool tool
Pool Volume Calculator
Enter the shape and size of the pool to see how many gallons and litres it holds. Every chemical dose depends on this number, so it is the first thing to get right.
Leave empty if the depth is the same throughout.
Your pool holds about
22,020
- Average depth 5.75 ft, surface area 512 sq ft.
- This assumes the floor slopes evenly from the shallow end to the deep end. A pool with a long flat shallow area and a short deep hopper holds less, so treat the answer as an estimate.
How it works
Pool Volume Is Surface Area Times Average Depth
A pool is a container, so its volume is the area of the water's surface multiplied by how deep the water is on average. Measured in feet, that gives cubic feet, and each cubic foot holds 7.48 US gallons. Measured in metres, it gives cubic metres, and each cubic metre holds 1,000 litres.
The surface area depends on the shape:
Round: 0.785 × diameter²
Oval: 0.785 × length × width
Kidney: 0.45 × (width A + width B) × length
Gallons = surface area (sq ft) × average depth (ft) × 7.48
The average depth is the shallow-end depth plus the deep-end depth, divided by two. Measure the depth of the water rather than the depth of the pool, because most pools are filled to the middle of the tile line rather than to the coping.
Worked example
A 32 by 16 Foot Pool, 3.5 to 8 Feet Deep
The surface area is 32 × 16, or 512 square feet. The average depth is (3.5 + 8) ÷ 2, or 5.75 feet. That makes 512 × 5.75 = 2,944 cubic feet, and 2,944 × 7.48 gives about 22,000 gallons, or roughly 83,400 litres.
With that number, the pool chemical calculator can size every dose for this pool. Press “Use this volume in the other calculators” above and the other tools on this site will start with it filled in.
Getting it right
When the Simple Formula Is Off
The formulas assume a regular shape and a floor that slopes evenly, which most residential pools roughly are. Three kinds of pool are worth a second look. A sport pool with a long flat shallow end and a short deep hopper holds less than the average depth suggests. A freeform pool with a beach entry or a large tanning ledge holds less than its outline suggests. A pool with an attached spa that shares its water needs the spa's volume added.
When accuracy matters, check the estimate against a dose you can measure. Salt is the cleanest test, because it doesn't get used up: add a weighed amount, let it circulate for a day, and compare how far the salt reading moved with what the salt calculator predicts for your estimated volume. If it moved further than predicted, the pool is smaller than you thought.
For pool service companies
The same maths runs at every stop in Pool Runs
These calculators use the dosing and saturation-index formulas built into the Pool Runs technician app. A tech logs the readings at the pool, the app works out the doses for that pool's own volume, and the visit lands in the customer's service history and report without anyone typing it up later.
- Readings and doses saved against each pool, with the saturation index for every visit
- A mobile app that works offline in a backyard with no signal
- Chemicals and parts tracked on every truck and in the shop
Try Pool Runs free
Free for 30 days, month to month, with white-glove onboarding to move your customers in.
Questions
Pool Volume Calculator FAQ
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