Seeding Rate Calculator

PLS is the product of germination percentage and purity percentage on the seed tag. It gives a true measure of viable, pure seed in the bag. When ordering native grasses, wild flower mixes, or forage species where purity can vary significantly, purchasing by PLS rather than bulk pounds guarantees a consistent target stand regardless of lot quality. For high-purity certified crop seed (wheat, soybean), purity is close to 100% and the germination adjustment alone is sufficient.

Always round up. Running short mid-field means a second trip to the dealer, a delay in planting the rest of the field, and an uneven planting date across the same crop. A partial extra bag can often be returned if unopened, or used to patch thin spots. The cost of an extra bag is far less than the yield loss from a thin stand.

No - the two serve different purposes. Calibration sets the rate the machine drops per acre (matching the target rate). This calculation sizes your total purchase so you have enough seed to cover the whole field at that rate. Both are necessary and they work together. Calibrate the drill, then use this calculator to confirm you ordered enough to finish the field.

Test it before planting. Germination declines with storage, especially in warm, humid conditions. A simple germination test: place 10-20 seeds on a damp paper towel in a warm location, fold, and check after the expected germination days for the species. Count the sprouts and calculate percent germination. If it is below 75-80%, consider ordering fresh seed or adjusting the rate upward significantly.