Seed Germination Rate Calculator
Calculate expected seedling count and germination rate from any seed packet.
Plan your planting for the seedlings you actually need.
Expected Seedlings
Seed germination rate — the percentage of seeds that successfully sprout — is a critical factor in planning your garden. Buying enough seeds, knowing how many seedlings to expect, and understanding how to improve germination rates all depend on this calculation.
What Affects Germination Rate?
Germination rate depends on several factors:
- Seed quality and age: Fresh seeds from reputable suppliers germinate at 80–95% for most vegetables. Seeds stored more than 2–3 years may drop to 50–60%.
- Species: Some plants germinate reliably (lettuce, beans, peas: 90%+), while others are more variable (parsley, peppers: 60–75%).
- Soil temperature: Most seeds germinate within a specific temperature range. Outside this range, germination slows dramatically or fails.
- Moisture: Seeds must absorb water (imbibition) to activate germination. Inconsistent moisture is a major cause of germination failure.
- Light/dark requirements: Some seeds need light to germinate (lettuce, basil); others prefer darkness (onions, phacelia). Most are neutral.
Typical Germination Rates by Vegetable
| Vegetable | Typical Germination % | Days to Germinate |
|---|---|---|
| Bean | 90–95% | 6–14 days |
| Pea | 85–90% | 7–14 days |
| Corn | 75–85% | 6–10 days |
| Tomato | 75–85% | 6–14 days |
| Pepper | 65–75% | 10–21 days |
| Lettuce | 90–95% | 5–10 days |
| Cucumber | 80–90% | 5–10 days |
| Carrot | 55–75% | 12–25 days |
| Parsley | 55–65% | 14–28 days |
| Onion | 70–80% | 10–20 days |
The Germination Rate Formula
Expected Seedlings = Number of Seeds × (Germination Rate / 100)
Seeds Needed for a Target Count = Target Seedlings / (Germination Rate / 100)
Improving Poor Germination
- Scarification: Scratching hard seed coats (e.g., morning glory) improves water penetration
- Soaking: Pre-soaking beans and peas overnight increases germination speed and rate
- Stratification: Cold-moist stratification breaks dormancy in many perennials and trees
- Fresh seed: Always use seeds within their recommended use-by date