Fertilizer Calculator

This works out how much fertiliser a target nutrient rate needs, and what rate a given amount actually delivers. Enter the area, the pounds of nitrogen, phosphate or potash you want per 1,000 square feet and the three numbers off the bag, and it returns pounds of product, bags, the area one bag covers and how much of each nutrient lands on the ground. The second mode starts from the product you already have and reports the rate it works out at. Phosphate and potash are reported as P2O5 and K2O the way a label does, with the elemental weights alongside.