How to use this calculator
Choose the recommended center-to-center spacing for your plants. Enter the minimum distance from a plant center to each bed edge. Choose inches or centimeters with the measurement-system control. Rows are aligned in a rectangular grid.
The formula
A worked example
A 120 × 48 inch bed with 12 inch spacing and a 6 inch margin has 10 positions along its length and 4 across its width: 40 plants total.
Assumptions & limitations
This is a geometric count, not a planting recommendation. It uses the same spacing in both directions and does not support staggered rows. The last row may leave more room than the specified minimum edge margin.
Common questions
Is the spacing between plant edges?
No. It is the distance from the center of one plant to the center of the next.
Why can the result be zero?
The chosen margin may leave no valid planting position along one side. Reduce the margin or use a larger bed.
Units reference
The calculation follows the method above. This reference supports the units and conversions.
NIST: units and conversion factors ↗Formula and worked example checked against automated test cases. About our methodology.