How the infinity pool volume calculator works
Work out the pool volume as length times width times average depth, then add the balance tank volume as its own length, width and water depth.
The calculator adds both figures before converting to gallons, so the dose you read is for the whole system.
The formula
Volume = (length x width x average depth) + balance tank volume
Measure: Pool length, width, average depth, balance tank size.
Worked example
A 35 by 16 foot pool at 5 feet average depth is 2,800 cubic feet. An 8 by 4 by 4 foot tank adds 128 cubic feet.
The 2,928 cubic foot total works out to about 21,903 gallons or 82,910 litres.
Tips before you measure
Measure the tank at its normal running level, not full to the brim. It sits part empty while the pump runs.
Test the water at the pool, not in the tank, since the tank lags behind on chemistry.
Infinity / Vanishing Edge pool volume FAQs
Do I have to include the balance tank?
Yes. It often holds 5 to 15 percent of the system water, which is enough to throw off doses.
What if the tank level moves?
Use the average running level. The swing between pump on and pump off is usually a few inches.
Does the spillover trough count?
The trough drains into the tank, so its water is already covered by the tank figure.
Other pool shapes
Not quite the right outline? The main pool volume calculator covers all 20 shapes with the same units and formulas.