How the plunge pool volume calculator works
Multiply length by width for the surface area, then by the water depth. Plunge pools normally have a flat floor, so a single depth reading works.
Multiply cubic feet by 7.48 for US gallons. Metric users can read litres and cubic metres straight from the results.
The formula
Volume = length x width x depth
Measure: Length, width, depth.
Worked example
A 12 by 7 foot plunge pool covers 84 square feet. With 4.5 feet of water that is 378 cubic feet.
That comes to about 2,828 gallons, or 10,700 litres.
Tips before you measure
Halve any dose instructions written for 10,000 gallon pools before you pour, then test and adjust.
Bench seats displace water. Subtract their footprint at seat depth if you want a tighter figure.
Plunge Pool pool volume FAQs
How many gallons is a typical plunge pool?
Most sit between 2,000 and 4,000 gallons. A 12 by 7 foot pool at 4.5 feet holds around 2,828 gallons.
Why does small volume matter for chemicals?
Doses scale with water. In a small pool a standard scoop of shock can push chlorine far past safe swimming levels.
Does a spa jet bench count?
Subtract the seat area at its own depth. It usually removes 100 to 200 gallons.
Other pool shapes
Not quite the right outline? The main pool volume calculator covers all 20 shapes with the same units and formulas.
