The core formula
Penn State explains that to apply 1.0 pound of nitrogen per 1,000 square feet with a 26-5-10 fertilizer, divide 1.0 by 0.26. That equals 3.8 pounds of product per 1,000 square feet. The first number on the bag is nitrogen percentage.
Why soil tests matter
Nitrogen drives growth, but phosphorus, potassium, pH, and soil conditions should not be guessed. UMN notes fertilizers can contribute to pollution if used incorrectly, and soil-test based decisions reduce waste.
Use product comparisons carefully
A cheaper bag is not always cheaper per pound of nitrogen. Use the fertilizer calculator to compare rates, then the Price Board to compare product prices and package sizes.