Plant Spacing Grid Calculator
Calculate how many plants fit in a garden bed from dimensions and spacing per plant.
Supports square grid and triangular offset patterns for maximum yield.
Plant spacing calculations determine how many plants fit in a garden bed and the optimal distance between them — balancing air circulation, root competition, sunlight access, and maximum yield per square foot.
Core formulas:
Row planting (rectangular grid): Plants per row = (Bed Length ÷ Spacing) + 1 Number of rows = (Bed Width ÷ Row Spacing) + 1 Total plants = Plants per row × Number of rows
Square foot gardening method: Plants per square foot = (12 ÷ Recommended Spacing)² (where spacing is in inches)
Triangular/offset planting (more efficient — ~15% more plants): Row spacing = Recommended Spacing × 0.866 (the sine of 60°)
Common vegetable spacing guide:
| Vegetable | Plant Spacing | Row Spacing | SFG per sq ft |
|---|---|---|---|
| Lettuce | 6–8 inches | 12 inches | 4 plants/sq ft |
| Carrots | 3–4 inches | 12 inches | 16 plants/sq ft |
| Tomatoes | 18–24 inches | 36–48 inches | 1 plant/4 sq ft |
| Peppers | 12–18 inches | 24 inches | 1 per sq ft |
| Basil | 12–18 inches | 18 inches | 1 per sq ft |
| Zucchini | 24–36 inches | 36 inches | 1 per 4–9 sq ft |
| Radishes | 2 inches | 12 inches | 36 plants/sq ft |
Worked example: A 4 ft × 8 ft raised bed, planting basil at 12-inch spacing: Plants per row = (8 ÷ 1) + 1 = 9 plants Number of rows = (4 ÷ 1) + 1 = 5 rows Total = 9 × 5 = 45 basil plants
Too dense vs. too sparse: Plants spaced too closely compete for water and nutrients, increasing disease risk. Plants spaced too far waste garden space. For most home gardeners, the square foot gardening method offers an excellent balance — high yield from small spaces with excellent companion planting flexibility.