Water Loss Calculator
The Water Loss calculator helps you figure out how many gallons of water your pool is losing each day based on a measured drop in water level. It supports two pool shapes — rectangular and round/circular — each using its own formula.
Rectangular Pool
Drag the slider to compare the input form and the calculated result.
- Desktop
- Mobile
The Formula
Length × Width × Water Level Drop (inches) × 0.6233 = Gallons per Day
The 0.6233 multiplier converts the cubic-inch drop into daily gallons for a rectangular shape.
Inputs
- Length — The length of the pool in feet
- Width — The width of the pool in feet
- Water Level Drop — How many inches the water level fell
- Over How Many Days — The number of days the drop was measured over
Round / Circular Pool
Drag the slider to compare the input form and the calculated result.
- Desktop
- Mobile
The Formula
Diameter × Diameter × Water Level Drop (inches) × 0.4893 = Gallons per Day
The 0.4893 multiplier accounts for the circular shape (derived from π ÷ 4 × 0.6233).
Inputs
- Diameter — The diameter of the pool in feet
- Water Level Drop — How many inches the water level fell
- Over How Many Days — The number of days the drop was measured over
All measurements should be entered in feet and inches as indicated. The calculator returns the estimated water loss in gallons per day.