Seed Spacing Calculator
Plants per row and per bed from your spacing plan.
Enter your values
Enter the bed length in ft.
Enter the bed width in ft.
Enter the in-row spacing in in.
Enter the row spacing in in.
Enter the germination rate in %.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Total plants
- 105
- Plants per row
- 21
- Number of rows
- 5
- Seeds to sow
- 124
- Density
- 2.63 plants per sq ft
Working
- 121 per row x 5 rows = 105 plants
Quick answer
Plants per row = row length divided by in-row spacing, plus one. Rows = bed width divided by row spacing.
plants = (row length / spacing + 1) x (bed width / row spacing)
At a glance
| What it does | Plants per row and per bed from your spacing plan. |
|---|---|
| Category | Home & DIY |
| Inputs needed | Bed length, Bed width, In-row spacing, Row spacing, Germination rate |
| Main output | Total plants |
| Formula | plants = (row length / spacing + 1) x (bed width / row spacing) |
| Cost | Free — no sign-up, no download |
How to use the Seed Spacing Calculator
- 1Enter the bed size and the spacing recommended on the seed packet.
- 2Row spacing can be tighter in raised beds than in field rows.
- 3Sow extra seed to allow for the germination rate you enter.
Inputs explained
- Bed length(ft)
- Enter the bed length in ft.
- Bed width(ft)
- Enter the bed width in ft.
- In-row spacing(in)
- Enter the in-row spacing in in.
- Row spacing(in)
- Enter the row spacing in in.
- Germination rate(%)
- Enter the germination rate in %.
Worked example
Using the values the calculator loads with:
Inputs
- Bed length10 ft
- Bed width4 ft
- In-row spacing6 in
- Row spacing12 in
- Germination rate85 %
Results
- Total plants105
- Plants per row21
- Number of rows5
- Seeds to sow124
- Density2.63 plants per sq ft
- 21 per row x 5 rows = 105 plants
Frequently asked questions
Can I plant closer than the packet says?
In rich raised-bed soil, yes - square-foot gardening spacings work well. In poor soil, crowding just gives you smaller plants.
Why sow more seed than plants I need?
Germination is never 100%, and thinning to the strongest seedlings gives a better crop than replanting gaps.
What do I need to enter into the Seed Spacing Calculator?
Just 5 values: bed length, bed width, in-row spacing, row spacing, germination rate. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Seed Spacing Calculator work out the answer?
Plants per row = row length divided by in-row spacing, plus one. Rows = bed width divided by row spacing. It applies the formula plants = (row length / spacing + 1) x (bed width / row spacing) and shows the working so you can check each step by hand.
Is the Seed Spacing Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.