Seed Rate Calculator

Calculate pounds of seed needed per acre based on crop type, target population, and germination rate.

Results

Visualization

How It Works

Seed rate is the number of seeds or pounds planted per acre. It depends on crop type, target plant population, seed size, germination rate, and tillage system. Over-seeding wastes money; under-seeding reduces yield.

The Formula

Seeds/Acre = (Target Population × Tillage Factor) / Germination Rate
Lbs/Acre = Seeds/Acre ÷ Seeds Per Pound

Variables

  • Target Pop — Desired final stand (corn: 32-36K, soybeans: 120-160K, wheat: 1.0-1.4M)
  • Germination Rate — Percentage of seeds that will sprout (from seed tag or germ test)
  • Tillage Factor — Increase rate 5-10% for reduced tillage due to harsher seedbed conditions

Example

Corn at 34,000 seeds/acre with 95% germination on 100 acres = 35,789 seeds/acre × 100 = 3.58M seeds ≈ 45 bags of 80K.

Tips

  • Increase seeding rate 5-10% for no-till due to reduced seed-to-soil contact.
  • Always run a germination test on carry-over seed — viability drops each year.
  • Corn hybrids vary in seed size; recalculate lbs/acre for each lot.
  • Soybeans can compensate for low populations by branching — avoid over-seeding.

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