Seed Quantity Calculator User Guide

What It Does:
Calculate the exact number of seeds needed for your garden based on area, plant spacing, germination rates, and extra buffer for replacements.

How to Use:

🧮 Calculator Tab

1. Select Crop Type:
   • Choose from 12 common vegetables
   • Auto-fills spacing and germination data
   • Displays crop-specific planting information
2. Enter Garden Area:
   • Input total planting area in square feet
   • For the specific crop you’re planting
3. Plant Spacing:
   • Auto-filled when crop is selected
   • Or enter custom spacing in inches
   • Distance between plant centers
4. Germination Rate:
   • Auto-filled with typical rate for crop
   • Or enter custom percentage (1-100%)
   • Accounts for seeds that won’t sprout
5. Extra Seeds Buffer:
   • 10% – Standard buffer
   • 20% – Recommended (default)
   • 30% – Safe margin
   • 50% – Maximum coverage
6. Calculate:
   • Click “Calculate Seeds”
   • Results show:
     • Plants needed at maturity
     • Total seeds to plant
     • Seed packets required
     • Complete planting plan

📊 Seed Reference Tab

Quick reference guide for common vegetables with planting specifications.

Information for Each Crop:

• Recommended plant spacing
• Germination rate percentage
• Planting depth
• Days to germinate
• Average seeds per packet

Crops Included:

• Lettuce (6-8″ spacing, 80% germination)
• Tomatoes (24-36″ spacing, 75% germination)
• Peppers (18-24″ spacing, 70% germination)
• Bush Beans (4-6″ spacing, 90% germination)
• Carrots (2-3″ spacing, 65% germination)
• Radishes (2″ spacing, 85% germination)
• Cucumbers (12-24″ spacing, 80% germination)
• Corn (8-12″ spacing, 75% germination)

Calculation Formula:

Step 1: Calculate Plants Needed

textPlants = (√Area / Spacing in feet)²

Step 2: Account for Germination

textSeeds for Germination = Plants ÷ (Germination Rate ÷ 100)

Step 3: Add Buffer

textTotal Seeds = Seeds × (1 + Extra % ÷ 100)

Example: 100 sq ft of lettuce

• Spacing: 6 inches (0.5 ft)
• Plants needed: 400
• Germination: 80%
• Seeds: 400 ÷ 0.8 = 500
• With 20% extra: 600 seeds

Germination Rates:

High (85-90%):

• Radishes, Beans, Squash

Good (75-85%):

• Lettuce, Cucumbers, Spinach, Corn

Moderate (70-75%):

• Tomatoes, Peppers, Peas, Onions

Lower (65-70%):

• Carrots, Parsnips

Quick Tips:

✅ Always buy 20-30% extra – For poor germination and replacements
✅ Plant 2-3 seeds per spot – Thin to strongest seedling
✅ Check expiration dates – Fresh seeds = better germination
✅ Succession plant – Sow lettuce/radishes every 2 weeks
✅ Store properly – Cool, dry, sealed container extends viability

Pro Tip: Most seed packets contain way more seeds than you need for a small garden. For example, a single lettuce packet with 500 seeds can plant a 200 sq ft area! Share extras with friends or save for succession planting throughout the season.

Angelina Everly

Angelina Everly leads the editorial desk at Live Green Gardens, blending practical plant care, hands-on product testing, and approachable outdoor styling. She focuses on step-by-step how-tos, buyer’s guides, and small-space makeovers that work in real life and real budgets. When she’s not comparing pruning shears or setting up a drip kit, you’ll find her creating cozy corners with planters, solar lights, and pollinator-friendly picks—always with clear pros/cons and safety notes so you can buy once and garden happy.