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Farming Calculators

Seed Rate Calculator

Seed needed per hectare from the target plant population and thousand-grain weight.

Enter values

Results update as you type.

Result

Seed rate

214.83 kg/ha

Total seed needed
4.297 tonnes
Seeds to sow
447.6 per m²
Per acre
86.94 kg/acre
Establishment factor
78.2 %
Extra seed for losses
46.83 kg/ha
Seed cost
$1,933.50
Cost per hectare
$96.68

About the Seed Rate Calculator

Seed needed per hectare from the target plant population and thousand-grain weight.

Also known as: sowing rate calculator, seed per hectare, drilling rate, kg seed per acre.

How to use this calculator

  1. Enter target plants, thousand grain weight, germination, field establishment and the other fields.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

kg/ha = target plants ÷ establishment × 10,000 × TGW ÷ 1,000,000

Worked example

Using the values pre-filled in the calculator above:

  • Target plants = 350 per m²
  • Thousand grain weight = 48 g
  • Germination = 92 %
  • Field establishment = 85 %
  • Area to sow = 20 hectares
  • Seed price per tonne = 450

the calculator returns:

  • Seed rate: 214.83 kg/ha
  • Total seed needed: 4.297 tonnes
  • Seeds to sow: 447.6 per m²
  • Per acre: 86.94 kg/acre