Plant Spacing Calculator
Work out how many plants fit in a bed, based on the bed's length and width, and the desired plant and row spacing.
How to use the plant spacing calculator
- Enter the length and width of the bed you're planting, in meters.
- Enter the desired spacing between each plant along a row, in centimeters.
- Enter the desired spacing between rows, in centimeters — the calculator shows the total number of plants that fit.
How the number of plants is calculated
The calculator works out the number of plants along the bed's length, and the number of rows along the width, and multiplies these:
Number of rows = (Bed width ÷ Row spacing) + 1
Total = Plants per row × Number of rows
The right plant spacing varies a lot by species and expected size — always check the recommended spacing on the seed packet or plant label for the best result. For example, lettuce typically needs 20–30 cm spacing, while larger plants like cabbage or squash need 40–60 cm or more.
Plan for the mature size, not the pot
The most common planting mistake is to space plants according to how big they are now. A perennial or shrub in a pot takes up little room, and a bed planted to that size looks right in the first season — only to become overcrowded within two or three years. Spacing should be set by the species' expected width at maturity, which is normally given on the label.
The planting pattern also affects how many plants are needed. Set in staggered rows rather than a square grid, the area is covered more evenly at the same spacing, and you avoid visible corridors between rows. For ground cover, where the aim is to close the surface quickly, staggered placement therefore usually gives a better result than a square grid.
Frequently asked questions
Why is an extra plant/row added beyond the simple division?
Because the first plant or row is placed right at the edge of the bed (distance 0), and the rest are spaced out from there. If you just divide the bed length by the plant spacing without adding 1, you lose the space for the very first plant in the row.
Should I use the same spacing between plants and between rows?
Not necessarily — it depends on the plant species and how you're growing. Many vegetables do well with a square or rectangular pattern with equal spacing both ways, while others (like rows of potatoes) often have wider row spacing than plant spacing within the row.
What happens if I plant too densely?
Overly dense planting creates competition for light, water and nutrients, which can produce smaller, weaker plants and increased risk of fungal disease due to poorer air circulation. Always follow the recommended spacing for the species you're growing.