Pond volume calculator.
Almost everything else about a pond - the pump you need, how many fish it can hold, how much treatment to add - hangs off one number: how much water it holds. Enter the shape and rough measurements for the volume, plus a sensible pump size and stocking guide.
Pump / filter:
Fish (rough guide):
Dosing treatments:
Rectangular and round ponds are plain geometry: length × width × average depth (the ellipse area for round and oval ponds). For a natural outline the calculator assumes the water fills about 80% of its length × width box - a rough allowance, so measure in sections for a closer number. These are estimates from average depth - real ponds vary with shelves and slopes, so treat the volume as a ballpark and round up for pumps and treatments, down for fish. The fish figure is a rough upper limit for cool, well-filtered water; understock for a healthier pond. Always dose treatments to the maker's instructions, not ours.