Plant Spacing Calculator
Calculate how many plants fit in a garden bed based on bed size and recommended plant spacing.
How to use this tool
- Enter the garden bed length and width in feet.
- Enter the recommended spacing between plants in inches (from the seed packet).
- The calculator shows total bed area and the number of plants that fit.
Find out exactly how many plants to buy before heading to the garden centre.
Formula
Bed area (ft²) = bed length (ft) × bed width (ft)
Plant count = floor( bed area ÷ (spacing (in) ÷ 12)2 )
Each plant is assumed to occupy a square cell of side equal to the recommended spacing distance.
How it works
This calculator divides the total bed area by the square footprint of a single plant (spacing × spacing) to estimate how many plants fill the bed in a uniform grid layout. Converting spacing from inches to feet allows consistent units throughout.
The result is floored to a whole number because partial plant positions are not usable. This approach assumes a simple square grid; triangular or offset planting can fit roughly 15% more plants in the same space.
Worked example
Worked example
- Inputs: 10 ft long × 8 ft wide bed, 12-inch plant spacing.
- Bed area = 10 × 8 = 80 ft².
- Spacing in feet = 12 ÷ 12 = 1.0 ft. Each plant occupies 1.0 × 1.0 = 1.0 ft².
- Plant count = floor(80 ÷ 1.0) = 80 plants.
Bed area = 80 ft²; plants needed = 80.
Key terms
- Plant spacing
- The recommended center-to-center distance between individual plants, usually given in inches on seed packets or plant tags.
- Square grid planting
- A layout where plants are placed at equal distances in both row and column directions, each occupying a square cell.
- Bed area
- The total surface area of the planting bed in square feet, calculated as length multiplied by width.
- Triangular (offset) planting
- An alternative layout where alternating rows are staggered, fitting more plants into the same area than a square grid.
Frequently asked questions
- How many plants fit in a garden bed?
- Divide the bed area (ft²) by the spacing area (plant spacing in ft, squared). For 12-inch spacing, each plant occupies 1 sq ft; an 80 sq ft bed holds 80 plants.
- What is the standard plant spacing?
- Spacing depends on the plant type: lettuce 6–8 in, tomatoes 24–36 in, peppers 18 in. Always check the seed packet or plant tag for recommended spacing.