Wheat Seeding Rate Calculator
Calculate lbs/acre based on TKW and Stand Targets
Plants per square foot (Optimal is typically 30-35)
Weight in grams of 1000 seeds
Survival rate after planting (typically 80-90%)
Seeding Rate (Lbs per Acre):
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Seeding Rate (Bushels per Acre):
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Total Seed Needed (Lbs):
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Total Seed Needed (Bushels):
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Seeds per Acre:
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Optimizing Your Wheat Seeding Rate
Calculating the precise seeding rate for wheat is crucial for maximizing yield potential. Unlike relying on a fixed "bushels per acre" rule of thumb, calculating your rate based on Thousand Kernel Weight (TKW) ensures you achieve the optimal plant stand regardless of seed size.
Why Calculation Matters
Seed size varies significantly between varieties and growing years. A variety with large seeds (high TKW) contains fewer seeds per pound than a variety with small seeds. If you plant both at the same weight (e.g., 120 lbs/acre), the large-seeded variety will result in a much thinner stand, potentially reducing yield.
Key Variables in the Calculation
- Target Plant Population: The number of plants you want established per square foot. For optimal yield potential, most agronomists recommend targeting 30 to 35 plants per square foot (approx. 1.3 to 1.5 million plants per acre).
- Thousand Kernel Weight (TKW): Measured in grams, this represents the weight of 1,000 seeds. Typical values range from 30g to 45g. The higher the TKW, the higher your seeding rate (lbs/acre) must be to achieve the same plant count.
- Germination Rate: Found on your seed tag. This is the percentage of seeds capable of sprouting under ideal conditions.
- Emergence/Survival Rate: This accounts for seed mortality in the field due to depth, soil temperature, crusting, or pests. A standard assumption is 80% to 90% emergence, though difficult conditions may require lowering this estimate (which increases the required seed rate).
The Math Behind the Calculator
This calculator determines the pounds of seed required per acre using the following logic:
Seeding Rate (lb/ac) = (Target Plants/ft² × 43,560 × TKW) ÷ (Germination % × Emergence % × 453,592)
By inputting your specific field parameters, you ensure that every acre has the optimal number of stems to maximize potential harvest volume.