Koi Pond Volume Calculator
Free Calculator
Estimate your pond's water volume
Choose your pond shape, enter its measurements, and get an instant estimate in US gallons and liters.
Estimated pond volume
This is a geometric estimate. Shelves, rocks, irregular walls, and equipment can reduce the actual water volume.
Next: Size Your Pond Pump →How the pond volume calculator works
The calculator estimates the volume of water contained by a simple geometric pond shape. For a rectangular pond it uses length × width × average depth. Circular ponds use the area of a circle × average depth, and oval ponds use the area of an ellipse × average depth.
Rectangular pond
Length × Width × Average Depth
Circular pond
π × Radius² × Average Depth
Oval pond
π ÷ 4 × Length × Width × Average Depth
How to measure an irregular koi pond
Most koi ponds are not perfect geometric shapes. Measure the longest length and widest width, then estimate the average water depth from several measurements around the pond. The calculator gives you a useful planning estimate, but a water meter used while filling the pond provides a more accurate measured volume.
Why pond volume matters
An accurate pond-volume estimate helps with filtration, pump sizing, water changes, stocking decisions, and any calculation based on the amount of water in the system.
Calculator note
This calculator provides an estimate for planning purposes. Actual water volume can differ because of pond shape, shelves, rocks, plumbing, filters, and other displacement.