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  1. Home
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Seed Spacing Calculator

Plan your garden layout with optimal spacing

Units

Square Foot Gardening

Use grid-based intensive spacing

Total Plants

4

Tomatoes

Plants per Row

4

Number of Rows

1

Plant Spacing

24"

Row Spacing

36"

Seeds Needed (with 20% extra)

5 seeds

Planting Breakdown

Plants per Row4
Number of Rows1
Total Plants4
Seeds Needed (+20%)5

Planting Grid Preview

Tomatoes Details

Plant Spacing24 inches
Row Spacing36 inches
Days to Harvest70 days
Area per Plant864 sq in

Quick Spacing Guide

2-3"

Carrots, Radishes, Beets

4-6"

Lettuce, Spinach, Onions

8-12"

Peppers, Basil, Marigolds

18-24"

Tomatoes, Broccoli, Squash

Example Calculations

1Tomatoes in an 8 × 4 ft Bed

Inputs

PlantTomatoes
Bed Length8 ft
Bed Width4 ft
Square Foot ModeOff

Result

Total Plants4
Plants per Row4
Number of Rows1
Plant Spacing24"
Row Spacing36"
Seeds Needed5

Bed = 96" × 48". Tomato spacing = 24" between plants, 36" between rows. Plants per row = floor(96 / 24) = 4. Number of rows = floor(48 / 36) = 1. Total = 4 × 1 = 4 plants. Seeds = ceil(4 × 1.2) = 5.

2Lettuce in a 10 × 4 ft Bed

Inputs

PlantLettuce
Bed Length10 ft
Bed Width4 ft
Square Foot ModeOff

Result

Total Plants80
Plants per Row20
Number of Rows4
Plant Spacing6"
Row Spacing12"
Seeds Needed96

Bed = 120" × 48". Lettuce spacing = 6" between plants, 12" between rows. Plants per row = floor(120 / 6) = 20. Number of rows = floor(48 / 12) = 4. Total = 20 × 4 = 80 plants. Seeds = ceil(80 × 1.2) = 96.

Frequently Asked Questions

Q

Why is plant spacing important?

Proper spacing ensures plants have enough room for roots, air circulation, and sunlight. Overcrowding leads to disease, stunted growth, and lower yields. Under-planting wastes garden space and resources.

Q

What is square foot gardening?

Square foot gardening divides beds into 1-foot squares, with each square planted with a specific number of plants based on spacing. It maximizes yield in small spaces using intensive, grid-based planting.

Q

How do I know what spacing to use?

Spacing depends on the plant's mature size. Large plants like tomatoes need 18-24 inches. Medium plants like peppers need 12-18 inches. Small plants like lettuce can be 4-6 inches apart.

Q

Should I buy extra seeds?

Yes, buy 20-30% more seeds than plants needed. Not all seeds germinate, and some seedlings may not survive transplanting. Having extras ensures you can fill gaps without delay.

Q

What is row spacing vs plant spacing?

Plant spacing is the distance between plants within a row. Row spacing is the distance between rows. Row spacing is usually wider to allow walking, watering, and harvesting between rows.

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Last Updated: Feb 12, 2026

This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.

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