Vegetable Seed Calculator

ft
in
Desired spacing between mature plants.
%
From seed packet or test. Typical: 70–90%.
Seeds sown per planting spot (thin to 1). Use 2–3 for reliability.
Biology

Calculate how many vegetable seeds to sow for a given row length or area based on plant spacing and germination rate.

Formula

Seeds = (Row Length × 12 ÷ Spacing) ÷ Germination Rate × Sow-per-spot
  • Germination rate: percentage of seeds expected to sprout.
  • Sow 2–3 seeds per spot for vegetables with low germination, thin to 1.
  • For direct seeding, always sow more than needed to ensure stand.

10 ft row, 4 in spacing, 80% germination

Inputs
  • Row Length: 10 ft
  • Final Plant Spacing: 4 in
  • Germination Rate: 80 %
  • Sow Per Spot: 2

Spots = (10×12)/4 = 30. Seeds = 30 / 0.8 × 2 = 75 seeds to sow.

Frequently asked questions

Should I sow more seeds than needed?
Yes — always over-sow by at least the inverse of the germination rate, then thin to desired spacing.
What germination rate should I assume?
Check the seed packet. Fresh seeds: 80–95%. Old seeds: 50–70%. Test old seeds before relying on them.