Calculator
Expanded clay calculator
Calculate the drainage layer and how much expanded clay (keramzyt) you need for a round pot.
Enter the inner diameter and height of your pot to estimate the drainage layer and the volume of expanded clay.
How to use the result
We recommend a drainage layer of about one fifth of the pot height — at least 2 cm and no more than 10 cm — so there is still plenty of room for roots.
Expanded clay keeps roots above water that collects at the base of the pot. It is light, reusable and does not decompose.
A drainage layer never replaces drainage holes. Tapered pots need slightly less material than the estimate.