Count positions, not just area
Use this calculator when you know the spacing for one crop and want to see how many final plants fit. Enter inside bed dimensions, then a crop preset or custom distances. For rows, enter both the distance along a row and the distance between rows. For blocks, the same distance applies in both directions.
Edge allowance is the minimum distance from the bed boundary to a plant centre. The default uses half the plant distance at each end and half the row distance at the sides. A custom allowance applies the same minimum to all four edges.
The placement calculation
If two edge allowances do not fit, that axis has zero positions. The two axis counts are multiplied. Any leftover interval is divided between the two edges so the grid is centred. The diagram, rows, and position list use this same result.
“Extra edge space” means the leftover length or width after the minimum margins and intervals. It is not the area between all plants. A zero custom margin is allowed, but centres on a bed edge may be impractical.
Check the numbers
An 8 × 4 ft bed is 96 × 48 inches. With 12-inch spacing and default half-spacing edges, there are 8 positions along the length and 4 rows: 32 positions. Centres start 6 inches from each edge.
Change only the row spacing to 24 inches in row mode: 8 positions × 2 rows = 16 plants. A 50-inch-wide block at 12-inch spacing still has 4 rows; its 2 extra inches are split, making the actual edge distances 7 inches.
Limits & mistakes to avoid
- Use final plant spacing, not the distance at which seeds are initially sown.
- Do not confuse inches, feet, and centimetres; changing a unit here converts entered measurements.
- Do not copy an in-row distance into both axes unless it is appropriate for block growing.
- A geometric fit does not assess soil, sunlight, airflow, cultivar, or access.
Bed sides are limited to 100 ft, spacing to 600 inches, and results to 10,000 positions. The planner uses the same grid engine with half-spacing margins. A custom edge allowance cannot be carried into its crop-strip layout without changing that rule.
Spacing questions
Why is the answer different from area divided by spacing?
Area division can count fractional plants and ignore edges. This tool counts whole positions that fit along each axis.
Can a very small bed hold one plant?
Only if the selected edge allowances fit. With default half-spacing margins, the bed must be at least one spacing interval wide and long.
Why does changing the preset change the count?
Each method has different published distances. Presets are starting points; any edit overrides the preset, and the result shows the actual distances used.