YielixSeed Rate Calculator: Germination-Adjusted Seeding Rates and Bags Needed
Calculate the exact seeding rate adjusted for germination, weight per hectare or acre, and number of bags needed for your field. This seed rate calculator uses thousand kernel weight (TKW) from your seed tag and target plant population to give you precise planting quantities. Crop-specific defaults are provided for corn, wheat, soybeans, canola, and more.
Inputs Explained
- Target Plant Population
- Your desired number of established plants per hectare or acre at emergence. Use extension recommendations for your crop and region as a starting point.
- Germination Rate (%)
- The percentage of seeds expected to germinate, found on the seed tag. Field germination is often 5-10% lower than lab germination.
- Thousand Kernel Weight (TKW)
- The weight of 1,000 seeds in grams, listed on the seed tag. Varies by crop: canola ~4 g, wheat ~35-45 g, corn ~280-360 g.
- Field Area
- Total area to be planted in hectares or acres. Used to calculate total seed weight and number of bags needed.
- Crop Selection
- Choose a crop to auto-fill target population and TKW with extension-recommended defaults. Override any value for your specific variety.
How This Calculator Works
Worked Example
Wheat at 300 plants/m² target, 90% germination, TKW of 40 g, on a 200 ha field
- 1. Convert target to plants/ha
300 plants/m² = 3,000,000 plants/ha
- 2. Adjust for germination
3,000,000 / 0.90 = 3,333,333 seeds/ha needed
- 3. Calculate weight per hectare
3,333,333 x 40 g / 1,000,000 = 133.3 kg/ha
- 4. Calculate bags for 200 ha
133.3 kg/ha x 200 ha = 26,667 kg total / 25 kg per bag = 1,067 bags
133.3 kg/ha seeding rate, 3,333,333 seeds/ha, 1,067 bags of 25 kg for 200 ha
How to Interpret Your Results
| Condition | What It Means |
|---|---|
| Seeding rate matches extension recommendation | Your inputs are within normal range for the selected crop. Proceed with confidence. |
| Seeding rate significantly higher than expected | Check that germination rate is not set too low. A 70% germination rate requires 43% more seed than a 100% rate. |
| Bags needed rounds up | Always order the ceiling number of bags shown. Running short mid-field is more expensive than a partial leftover bag. |
Common Mistakes to Avoid
Using lab germination rate without field adjustment
Field germination is often 5-10% lower than the seed tag value. If plant counts consistently fall short, reduce the germination input to 80-85%.
Confusing seeds per area with plants per area
Target plant population is the desired stand after emergence. Seeds per area is higher because not all seeds germinate.
Using TKW from a different variety or year
TKW varies between varieties and growing years. Always use the value printed on your actual seed tag for the lot you are planting.
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Related Guides
Calculating Seed Rates and Plant Populations
Learn how thousand kernel weight, germination rates, and row spacing affect your seeding decisions and final plant stand.
Understanding Growing Degree Days for Crop Management
Learn how GDD works, base temperatures by crop, and how to use growing degree day tracking for planting and harvest decisions.