How to Calculate Seeding Rate: Seeds per Meter and kg per Hectare

Seed is one of the biggest input costs, and the target is a number of plants, not seeds. Getting from one to the other means accounting for seeds that don't germinate and seedlings that don't survive.

The steps

1. Seeds per hectare = target plants per ha ÷ (germination × field survival).
2. Seeds per meter of row = seeds per ha × row spacing (m) ÷ 10,000.
3. kg per hectare = seeds per ha × thousand-seed weight (g) ÷ 1,000,000.

Example: soybeans

Target 300,000 plants/ha, rows 50 cm, germination 85%, field survival 90%, thousand-seed weight 160 g. In the seeding rate calculator:

• Combined efficiency: 0.85 × 0.90 = 76.5%
• Seeds per hectare: about 392,000
• Seeds per meter: 19.6 (for 15 plants per meter)
• Seed: about 62.7 kg/ha

Example: corn

Target 80,000 plants/ha, rows 76 cm, germination 95%, survival 95%, thousand-seed weight 330 g → about 88,600 seeds/ha, 6.7 seeds per meter and 29 kg/ha. Corn is usually bought by seed count, so the seeds-per-hectare figure matters most.

Where the numbers come from

• Germination: the seed bag label or a lab test.
• Thousand-seed weight: also on the label, and it varies between lots — always use the current lot's figure.
• Field survival: 85–95% is common; lower in cold, wet or crusted soils and with pest pressure.

Check the planter in the field by counting seeds over a few meters of row. After harvest, the yield and moisture calculator helps you see how the season really turned out.