Rectangular
The most common domestic pool. Measure inside length, inside width and average depth. Volume = length × width × average depth.
Pool shapes
The calculator supports four outlines. Choose the closest match; for anything else, use irregular mode and add sections until the sketch covers the water.
Always convert to metres first, then convert cubic metres to litres by multiplying by 1,000.
Circular
Above-ground round pools and some spa-style plunges. Measure the diameter across the centre (twice, then average) and the average depth. Volume = π r² × depth.
Oval
Treated as an ellipse, not a rectangle with round ends. Measure the longest inside length and the widest inside width. Volume = π × a × b × depth, with a and b as the semi-axes.
Irregular
Kidney, freeform, L-shape and pools with a separate spa. Split the outline into rectangles, circles and ovals, calculate each section, then add them. Overlap slightly rather than leave a gap.
Ready to enter numbers? Open the volume calculator or read the full formula guide.