Work out how much fertilizer to apply for a target nitrogen rate.
A fertilizer's nitrogen analysis tells you how many pounds are actually nitrogen. Dividing the desired nitrogen by the analysis gives the pounds of product to spread per 1000 square feet. Applying by analysis rather than by volume prevents both starving plants and burning them with excess nitrogen, which also wastes money.
Fertilizer NPK Rate
Fertilizer = target N ÷ (N% ÷ 100), scaled to the area
Fertilizer = target N ÷ (N% ÷ 100), scaled to the area A fertilizer's nitrogen analysis tells you how many pounds are actually nitrogen. Dividing the desired nitrogen by the analysis gives the pounds of product to spread per 1000 square feet.
Applying by analysis rather than by volume prevents both starving plants and burning them with excess nitrogen, which also wastes money.
This calculator takes 3 inputs: Garden area, Nitrogen analysis, Target nitrogen. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.