Pond Calculators
Numbers for a garden pond: how much water it holds, the liner and pump to buy, how many fish it carries, and how much salt to add.
- Pond volumePond volume in gallons and liters, and the water surface areaOpen calculator
- Pond liner sizeThe length and width of liner to buy, overlap includedOpen calculator
- Pond pump sizeThe flow a pump must deliver, and the head height to check it atOpen calculator
- Pond fish stockingHow many goldfish or koi a pond carries, with a careful number and a limitOpen calculator
- Pond saltThe weight of salt for a pond, in total and per dayOpen calculator
Two depths, two jobs
Volume uses the average depth
A pond with sloping sides and plant shelves holds far less water than its deepest point suggests. Measure the water depth in several places and average the readings. That figure, times the water surface, is the volume you dose treatments and size pumps by. Work out your pond volume
The liner uses the deepest point
A liner has to reach the very bottom, so its size comes from the deepest point of the hole, counted twice: down one side and up the other. Add the overlap that holds the edge down, round up to the size sold, and trim only once the pond is full. Work out your liner size
Feet and meters
The pond calculators work in feet and US gallons or in meters and liters. Switch units at the top of any calculator and every number changes with you. One cubic foot of water is 7.48 US gallons; one cubic meter is 1,000 liters and weighs one tonne.