Free tool
Plant spacing calculator.
Enter your pot and a crop. See how many plants fit, plus a simple grid that keeps an edge margin so nothing is cramped against the rim.
Results
2
plants fit
How spacing works in a pot
In the ground, seed packets list center-to-center spacing so mature plants have airflow and root room. In a pot you still use that spacing, and you also keep an edge margin — about 2 inches by default — so outer plants aren’t pressed into the rim, where soil dries fastest.
The calculator places plant centers inside that margin. Round pots drop any center that would fall outside the usable circle. Treat the result as a plan, then give vigorous varieties extra room if the leaves start to crowd.