Germination Rate Calculator
Enter the number of germinated seeds and the total sown to compute the germination rate = germinated ÷ sown × 100%, and show the ungerminated count, for evaluating seed quality and sowing amount.
Input Data
Results
At a glance:Germination rate (germination percentage) is the percentage of normally germinated seeds among the total tested seeds under set conditions: germination% = germinated ÷ sown × 100. It is the most basic and direct indicator of seed vigor and quality, and the basis for estimating actual sowing amount in agriculture and horticulture. A standard germination test takes a fixed number (e.g. 50, 100, or 400) of seeds, cultured under specified temperature, humidity, and light for a period, then counts seeds that normally produced root and shoot. Higher germination means better vigor; if a batch is low, you must increase sowing proportionally to reach the target plant count. Related is 'germination energy' (the proportion germinating within a shorter time, reflecting uniformity and vigor).
Formula
Germination rate: germination% = germinated ÷ sown × 100.
Ungerminated count: sown − germinated.
Compensatory sowing: target plants ÷ (germination% ÷ 100).
$$G\% = \frac{n_{sprouted}}{n_{sown}} \times 100$$$$n_{seed} = \frac{n_{target}}{G\% / 100}$$How to Use
- Enter the number of normally germinated seeds (germinated).
- Enter the total seeds sown/tested (sown).
- The tool instantly shows germination rate (%) and ungerminated count; higher rate means better seed vigor.
Germination rate grades and suggested compensatory sowing
| Germination rate | Grade | Suggested action |
|---|---|---|
| > 90% | Excellent | Direct sowing at standard density |
| 80–90% | Good | Slight increase in sowing amount |
| 60–80% | Fair | Increase sowing ~25–60% |
| < 60% | Poor | Raise sowing substantially or change seed lot |
Grades are general horticultural references; actual thresholds vary by crop and seed standard. Always pair with a seedling survival rate in the field.
Case Studies
Standard germination test
Sow 50 seeds; after the test period, 45 germinated normally.
Germination rate = 45 ÷ 50 × 100 = 90%.
Ungerminated = 50 − 45 = 5 seeds; 90% meets a good commercial seed standard, suitable for direct sowing.
Compensatory sowing for a low-germination batch
A batch germinates only 60%; you need 100 seedlings.
Sowing amount = 100 ÷ (60 ÷ 100) ≈ 167 seeds needed.
Rather than sowing 100, add about 67 more to offset the 40% loss and hit the target stand.
FAQ
What does germination rate mean?
It is the percentage of seeds that germinate normally among those sown under set conditions, germination% = germinated ÷ sown × 100. It directly reflects seed viability and quality; the higher the rate, the fewer seeds you waste and the closer the stand matches your plan.
What is the difference between germination rate and germination energy?
Germination rate counts the final total that germinated over the whole test; germination energy counts the proportion that germinated within a shorter, earlier window, reflecting speed and uniformity of emergence and thus early vigor. High energy means neat, synchronized seedlings, important for mechanical transplanting.
How many seeds for a standard germination test?
Commonly 50, 100, or 400 seeds, depending on seed size and standard. Larger samples give more stable rates. Keep conditions (temperature, humidity, light) consistent and count only seeds with normal root and shoot as 'germinated'.
How to compute compensatory sowing?
Determine the target plant count, then sowing amount = target ÷ (germination% ÷ 100). For example a 70% batch to get 100 plants needs 100 ÷ 0.7 ≈ 143 seeds. This offsets the ungerminated loss so the final stand meets the plan.
Why might germination be low?
Common causes: aged or improperly stored seeds (humidity, high temperature shorten viability), dormancy needing stratification or scarification, disease or pest damage, unsuitable temperature/moisture, or physical damage. Pre-soaking, low-temperature stratification, or fungicide treatment can raise germination.
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References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.