Garden Row Spacing Calculator
Bed and spacings to per-row, rows, and totals.
What it does
Row gardening lives or dies on spacing. Two divisions turn bed size and packet numbers into plants per row, row count, and the bed total. Seed shopping without it means gaps or jungle.
The tool above floors bed length by in-row spacing and bed width by between-row spacing, then multiplies. Imperial mode speaks feet and inches; metric mode speaks meters and centimeters with identical results.
Extension planting guides from Clemson to Georgia teach this same packet math with crop tables behind the spacings. Small roots pack at inches; sprawling corn and squash demand feet. The engine stays neutral while packets supply the numbers.
Leftover inches are normal: a 20-foot row at 6-inch spacing fits exactly 40, and anything shorter wastes the tail. Spend the tail on paths, then thin seedlings to spacing instead of past it.
How to use
- Pick imperial (ft, in) or metric (m, cm).
- Enter bed length and width.
- Enter in-row spacing from the packet.
- Enter between-row spacing.
- Read per-row, row count, and total.
- Buy seed and starts to the total.
Formula
- length
- Bed length along the rows.
- width
- Bed width across the rows.
- in-row
- Plant-to-plant gap along the row.
- between
- Row-to-row gap.
All units convert inside: feet times 12 over inches, meters times 100 over cm. Flooring drops partial slots too short for one more plant. Edge paths and bed frames eat extra inches beyond the math.
Worked example
Example: 20 by 4 ft bed
20 by 4 ft bed, 6 in apart in rows 12 in apart.
- Bed is 20 ft long and 4 ft wide.
- In-row 6 in: 20 x 12 / 6 = 40 plants per row.
- Between rows 12 in: 4 x 12 / 12 = 4 rows.
- Total: 40 x 4 = 160 plants.
- Thin to the spacing, not past it.
Reference table
| Crop | In-row | Between rows |
|---|---|---|
| Carrots, onions | 2 to 4 in | 12 in |
| Beans, beets | 4 to 6 in | 18 in |
| Lettuce | 8 to 12 in | 12 to 18 in |
| Corn | 10 to 12 in | 30 to 36 in |
| Squash, melons | 24 to 36 in | 48 to 72 in |
Limits
- Spacing needs packet or guide values per crop.
- Ignores paths, frames, and edge loss.
- No germination or thinning losses counted.
- Succession timing sits outside the count.
Common mistakes
- Eyeballing instead of measuring.
- Crowding rows for airflow crops.
- Counting partial tail slots.
- Mixing inches with feet mid-math.
- Skipping thinning after emergence.
Try it yourself
Quick checks. Answers sit tucked under each question.
10 by 3 ft bed at 4 in by 9 in?
Per row is floor(120 / 4) = 30. Rows are floor(36 / 9) = 4. Total is 120 plants.
3 by 1 m bed at 10 cm by 25 cm?
Per row is floor(300 / 10) = 30. Rows are floor(100 / 25) = 4. Total is 120 plants.
Questions
In-row vs between-row: which is which?
Seed packets list both: in-row for plants along the row, between-row for row gaps. Crowding either way shrinks harvests and feeds disease. Measure, don't eyeball.
Do spacings differ by crop?
Yes, and most should: carrots and onions near 2 to 4 inches, beans near 4 to 6, corn near 10 to 12. Tight rows suit small roots; sprawlers need air.
What about leftover inches?
Floor division: a 20-ft row at 6-inch spacing fits exactly 40, with the leftover inches too short for one more. The tool floors automatically.
Does metric work the same?
Same math, metric units: meters to centimeters inside the tool. A 6 m row at 15 cm gives 40 per row, mirroring the imperial example plant for plant.
How do succession and interplanting fit?
Succession: replant each harvested row within days. Interplanting: tuck fast radishes between slow carrots. Both reuse the same per-row math.
How deep do seeds go?
Deeper for big seed (about twice the seed diameter), barely covered for tiny seed. Spacing feeds sideways room; depth feeds emergence.