Seed Spacing Calculator
Common Vegetable Seed Spacing
Standard spacing for raised bed gardens
| Vegetable | In-Row Spacing | Row Spacing | Plants/Sq Ft | Depth |
|---|---|---|---|---|
| Lettuce | 6" | 12" | 4 | 1/4" |
| Carrots | 2" | 6" | 16 | 1/4" |
| Radishes | 2" | 6" | 16 | 1/2" |
| Beans (bush) | 4" | 18" | 2 | 1" |
| Peas | 3" | 18" | 2.7 | 1" |
| Tomatoes | 24" | 36" | 0.17 | 1/4" |
| Peppers | 18" | 24" | 0.33 | 1/4" |
| Squash | 36" | 48" | 0.08 | 1" |
How We Calculate This
This seed spacing calculator uses established formulas and industry-standard data to provide accurate estimates.
- Enter your specific values into the calculator fields above
- Our algorithm applies the relevant formulas using your inputs
- Results are calculated instantly in your browser — nothing is sent to a server
- Review the detailed breakdown to understand how each factor affects your result
These calculations are estimates based on standard formulas. For critical decisions, always consult a qualified professional.
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This calculator determines how many rows fit in your bed, how many seeds per row, and the total seeds needed accounting for germination rate.
The basic rule:
- Number of rows = bed width (inches) ÷ row spacing + 1
- Seeds per row = bed length (inches) ÷ seed spacing + 1
- Total planting spots = rows × seeds per row
- Actual seeds needed = planting spots ÷ (germination rate / 100)
- Plants per square foot = 144 ÷ (seed spacing × row spacing)
In square foot gardening, spacing is measured from center to center in a grid pattern rather than traditional rows. This often fits more plants in the same space.
When Would You Use This Calculator?
This seed spacing calculator is designed for anyone who needs quick, reliable estimates without complex spreadsheets or professional consultations.
- When you need a quick estimate before committing to a purchase or project
- When comparing different options or scenarios side by side
- When planning a budget and need to understand potential costs
- When you want to verify a quote or estimate you've received from a professional
- When teaching or learning about the concepts behind these calculations
Frequently Asked Questions
How do I know what spacing to use?
Check your seed packet — it lists both in-row spacing and row spacing. Common examples: lettuce 6" apart in 12" rows, tomatoes 24" apart in 36" rows, carrots 2" apart in 6" rows.
Should I plant extra seeds for germination rate?
Yes. If germination rate is 85%, plant about 18% more seeds than spots needed (1/0.85 = 1.18). You can thin seedlings later. Fresh seeds have higher germination rates than old seeds.
What is succession planting?
Planting the same crop every 2-3 weeks extends your harvest season. Instead of 100 lettuce plants maturing at once, plant 25 every two weeks for a continuous supply over 8+ weeks.
Can I plant closer in raised beds?
Yes. Raised beds with good soil can use the intensive/square foot spacing, which is about 75% of traditional row spacing. The rich soil and no foot traffic allow tighter planting.