FREE POND CALCULATOR
Pond Filter Calculator
Enter your pond volume and fish stocking level to understand which filter capacity rating you should compare when choosing a filtration system.
Not sure of your pond's volume? Use the Pond Volume Calculator.
These factors do not create a universal filter-size multiplier, but they can affect the equipment and setup your pond needs.
Filter sizing guidance
Enter your pond volumeYour recommendation will appear here.PONDSTUFF GUIDE
How to choose the right filter capacity
Start with the most accurate estimate you can get of your pond's water volume. If you do not know it, use our Pond Volume Calculator.
Check the correct capacity rating
Do not assume the largest capacity number printed on a filter applies to every pond. Look for the manufacturer's rating that matches your pond's fish stocking level.
Fish load matters
Fish increase the biological load placed on a filtration system. Koi and heavily stocked ponds therefore need to be assessed using the appropriate manufacturer rating rather than a fishless-pond capacity.
What about the pump?
Filter capacity and pump flow are related, but they are not the same measurement. Pump selection also needs to account for the filter's permitted flow range, pipework, restrictions and the height to which water must be lifted.
Use the result as a specification
The calculator is designed to give you a specification to compare against product information, rather than pretending every manufacturer rates its filters in exactly the same way.