Calculator
Plant Spacing Calculator
Choose what you are planting and the length and width of the bed. The calculator uses a practical in-bed spacing for that crop, counts how many plants fit on a full grid, and draws a top-view sketch of the bed with a dot for each plant. It does not pack leftovers. A bed narrower than the spacing still gets a single row; those plants hang over the sides. Real beds also need room for aisles, trellises, and airflow.
Your result
Tomatoes (determinate / bush)
8plants
Top view · each dot is one plant · 2 across × 4 along
4 ft wide
8 ft long
- Spacing used
- 24 inCenter to center
- Bed area
- 32 sq ft
Cage or stake each plant. 18 inches is possible if you prune and keep airflow.
How this calculation works
Each crop has a default center-to-center spacing in inches. Plants along a side = floor(side length ÷ spacing), with a minimum of 1 if that side is narrower than the spacing. Total = plants along length × plants along width. Tomato, lettuce, and cucumber types have separate defaults because bush, vining, leaf, and head plants do not use the same number.
Example: 4×8 bed, determinate tomatoes
Determinate tomatoes use 24-inch spacing. 4 ft is 48 inches (2 plants across). 8 ft is 96 inches (4 plants along). Estimated total: 8 plants, shown as two rows of four dots. A 4×1 bed is too narrow for two rows, so the same crop becomes a single row of 2 — the plants hang over the 1-ft sides. Indeterminate vines would use 30 inches and fit fewer.
Frequently asked questions
Why don’t I enter the spacing myself?
Most people do not walk around with a spacing chart. Pick the crop; the tool uses a practical raised-bed default. If your variety is extra compact or extra large, use fewer plants than the count, not more.
Why is the grid count sometimes lower than I expect?
The calculator uses full spacing intervals that fit inside the bed. It does not squeeze a partial extra plant into leftover inches. If you plant on the edges, you may fit one more in a row, at the cost of airflow.
Why does a narrow 4×1 bed still show plants?
Spacing is the gap between plants, not a minimum bed width. If one side is narrower than the spacing, the calculator plants a single row down the center. A 4×1 bed of determinate tomatoes (24 in) is two plants in a line. They will hang over the sides; that is expected in a skinny bed.
Can I plant closer than the result?
You can, and people do in square-foot gardens. Closer spacing means more disease pressure and smaller plants. The defaults here lean toward airflow in a raised bed, not maximum packing.