🌾 Calculateur de Semis

Calculate seed requirement based on plant spacing, row spacing, 1000-grain weight and germination rate.

Calculate your exact seed requirement in seconds. Enter field area, plant spacing, row spacing, 1000-grain weight, and germination rate to get plants per hectare, total seeds needed, and seed weight in kilograms. No more guessing — plant the right population for maximum yield.

You planted 30 kg of corn seed last spring only to find 20% empty patches at emergence. The germination test said 85%, but you planted as if it were 100%. That mistake cost you 12 bushels per acre. This calculator accounts for germination rate automatically, so you always seed the right amount.

📊 Results

Plants per Hectare-
Total Theoretical Plants-
Seeds Needed (incl. germination)-
Seed Weight Required-

About Seed Rate Calculation

Accurate seed rate ensures optimal plant population for maximum yield. Too dense causes competition; too sparse wastes land.

Formula

  • Plants/ha = 10,000 ÷ (plant spacing × row spacing in meters)
  • Seeds needed = total plants ÷ germination rate
  • Seed weight (kg) = seeds ÷ 1000 × 1000-grain weight ÷ 1000

Reference 1000-Grain Weights

  • Corn: 250-350g | Wheat: 35-50g | Rice: 25-30g
  • Soybean: 150-200g | Peanut: 500-900g

Frequently Asked Questions

Q: How does germination rate affect seed rate?

A: If germination is 85%, you need 15% more seed to achieve the same plant population. The calculator divides theoretical plants by germination rate to give actual seeds needed. Always test seed before planting — bag labels can be optimistic.

Q: What is a good 1000-grain weight for common crops?

A: Corn: 250-350g, wheat: 35-50g, rice: 25-30g, soybean: 150-200g, peanut: 500-900g. 1000-grain weight varies by variety and growing conditions — weigh a representative sample from your own seed lot for accuracy.

Q: Should I add a safety margin to the calculated rate?

A: Yes. Add 5-10% extra to account for field losses, bird damage, and uneven germination. But do not exceed 15% — overplanting causes competition and reduces yield. The calculator already includes germination adjustment, so the margin is for field losses only.