Garden Row Spacing Calculator
Calculate how many planting rows fit in a garden bed based on bed length and the spacing between rows.
How to use this tool
- Enter the garden bed length in feet (the direction rows run across).
- Enter the spacing between row centres in inches.
- The calculator returns the number of rows that fit and the total span they occupy.
Plan your vegetable garden rows efficiently to maximise planting space.
Formula
Row count = floor( bed length (ft) ÷ (row spacing (in) ÷ 12) ) + 1
Total row span (ft) = (row count − 1) × (row spacing (in) ÷ 12)
The first row sits at position 0 (the bed edge), which is why 1 is added to the floor division.
How it works
This calculator places the first row at the very start of the bed and then fits as many additional rows as the remaining length allows at the given spacing, adding 1 to account for that first row at position zero.
Total row span is the distance from the first row to the last, which is always less than or equal to the bed length. In practice, gardeners often leave a half-spacing buffer at each end of the bed, which would reduce the row count by one.
Worked example
Worked example
- Inputs: 20 ft bed length, 18-inch row spacing.
- Row spacing in feet = 18 ÷ 12 = 1.5 ft.
- Rows from floor division = floor(20 ÷ 1.5) = floor(13.33) = 13; add 1 for the first row = 14 rows.
- Total row span = (14 − 1) × 1.5 = 13 × 1.5 = 19.5 ft.
Number of rows = 14; total row span = 19.5 ft.
Key terms
- Row spacing
- The center-to-center distance between adjacent planting rows; seed packets list this separately from in-row plant spacing.
- In-row spacing
- The distance between individual plants within a single row; distinct from row spacing.
- Bed length
- The dimension of the garden bed measured along the direction the rows run.
- Edge buffer
- The gap left between the outermost row and the bed edge; not included in this calculation but commonly used in practice to allow access and mulching.
Frequently asked questions
- How many rows fit in my garden bed?
- Divide the bed length by the row spacing in feet, then add 1 for the first row. Example: a 20 ft bed with 18-inch spacing: 20 ÷ 1.5 = 13.3, plus 1 = 14 rows.
- What is the best row spacing for vegetables?
- Spacing depends on the crop: lettuce 12 in, carrots 12–18 in, peppers 18 in, tomatoes 24–36 in. Check your seed packet or variety recommendations.