Plant Spacing Calculator

How to use the plant spacing calculator

Enter bed dimensions in feet and the recommended spacing between plants in inches (from seed packets or extension guides). Select row spacing for traditional rows or square-foot for intensive grid planting.

Results show approximate total plants plus row and column counts for layout planning.

Plant spacing formulas

Row spacing: Columns = Floor(Bed length in inches ÷ Spacing). Rows = Floor(Bed width in inches ÷ Spacing). Total plants = Columns × Rows.

Square-foot method: Plants per sq ft = Floor(12 ÷ Spacing) × Floor(12 ÷ Spacing). Total plants = Bed area (sq ft) × Plants per sq ft.

• Row: plants = ⌊L×12/s⌋ × ⌊W×12/s⌋
• Square-foot: plants/sq ft = ⌊12/s⌋²
• Spacing is center-to-center unless your seed packet says otherwise
• Use plant spacing with seed quantity to plan purchases

Worked example

An 8 ft × 4 ft bed with 12-inch spacing using row layout: Length = 96 in, width = 48 in.

Columns = 96 ÷ 12 = 8. Rows = 48 ÷ 12 = 4. Total plants = 8 × 4 = 32 plants.

Row spacing vs square-foot gardening

Row spacing mirrors traditional parallel rows with the same distance between plants in all directions. Square-foot gardening divides the bed into 1-foot squares and packs plants at the maximum density each square allows.

At 12-inch spacing both methods yield the same count. At 6-inch spacing, square-foot gives 4 plants per square foot (2×2 grid), maximizing density in intensive beds.

Spacing guidelines by crop

Follow seed packet spacing first — it accounts for mature plant size. Tomatoes often need 18–24 inches; lettuce and radishes fit at 4–6 inches in intensive layouts.

• Stake or trellis vining crops to save horizontal space.
• Wider spacing improves airflow and reduces disease in humid climates.
• Combine with harvest date calculator to stagger plantings.
• Use seed quantity calculator to buy enough seed for the plant count.