Plant Spacing Calculator
Find how many plants fit in a garden bed at the spacing on the seed packet, in a square grid, staggered rows or rows with a wider path between them.
Given on the seed packet or plant label, in cm (or inches).
Plants needed
40
- Rows
- 4 30 cm apart
- Plants in a full row
- 10
- Plants per square metre
- 11.1
A 3 × 1.2 m bed takes 40 plants at 30 cm spacing in a square grid.
How it's worked out
- Plants along the bed
300 cm ÷ 30 cm, rounded down10 - Rows across the bed
120 cm ÷ 30 cm, rounded down4 - Plants
4 × 1040
- Each plant sits half a spacing in from the edge, so it doesn't crowd the path or the next bed. Buy a few extra to replace any that fail.
How it is worked out
Plants along the bed = length ÷ spacing, rounded down; rows = width ÷ gap between rows, rounded down. In a staggered layout the rows sit 0.866 × spacing apart and every other row is shifted by half a spacing, so it can hold one fewer plant.
Questions people ask
How many plants fit in a 3 m by 1.2 m bed at 30 cm spacing?
40 plants in a square grid: 10 along the bed in 4 rows.
Does staggering plants fit more in?
In bigger beds, yes. In a 10 m by 10 m area at 30 cm, a staggered layout fits 1,235 plants against 1,089 in a square grid. In small beds the gain can disappear.
Why start half a spacing from the edge?
So the outer plants have as much room as the inner ones and don't spill over the path.
What spacing should I use?
The one on the seed packet or plant label. Where it gives one spacing for plants and another for rows, choose the rows layout.
About this calculator
Formula and rules last checked 10 November 2026Written and tested by the CalculatorDex teamReport a problem