Seeding calculator
Seeding rate calculator
Estimate seed pounds from acres, target seeds per acre and thousand kernel weight. The defaults below come from the seeding-rate reference table, but your seed tag is the best TKW source.
Calculate seed needed
Common defaults
- Soybean: 140k–170k live seeds/acre
- Corn: 30k–36k seeds/acre
- Wheat: 1.25–2.2M seeds/acre
- Lentil: about 500k plants/acre target
Formula
seed kg = acres × seeds/acre × TKW(g) ÷ 1,000,000
Seeding rate by crop
| Crop | Seeding rate | Unit | Indicative TKW | Notes |
|---|---|---|---|---|
| Wheat | 1.25–2.2M | seeds/acre | 30–45 g | Spring/winter; use seed tag for real TKW |
| Barley | 50–90 | lb/acre | 40–55 g | Small grain or cover crop |
| Oats | 30–70 | lb/acre | 27–38 g | Drilled lower, broadcast higher |
| Soybean | 140k–170k | live seeds/acre | 133–206 g | Varies by maturity, region and planting date |
| Corn | 30k–36k | seeds/acre | 250–380 g | Hybrid-dependent; rainfed often lower |
| Canola | 5–7 | lb/acre | 3–6 g | Often better planned as plants/sq ft |
| Pea | 300k–350k | plants/acre target | 90–280 g | lb/acre varies widely with seed size |
| Lentil | 500k | plants/acre target | 40–70 g | Target about 12 plants/sq ft |
| Cover crop | 15–100 | lb/acre | varies | Depends on species and mixture |
FAQ
What is TKW?
TKW means thousand kernel weight, usually in grams per 1,000 seeds.
Should I use the default TKW?
Use the seed tag when available. The table values are defaults for estimation.
Why do some crops use seeds/acre and others use lb/acre?
Some crops are commonly planned by population targets, while others are often sold and planted by weight. The calculator can translate population and seed size into pounds.