Fertilizer manufacturers, who usually deal with large-scale, commercial users of their products, publish charts that provide the mass of fertilizer to make up solutions of fixed nitrogen concentration (ppm N), whether mixed for use, a gallon at a time, or when mixing a concentrate for further dilution.
Unfortunately, hobby growers are often left in the dark, not really knowing how much fertilizer to mix per gallon, so must estimate, using fractions of the instructions provided on the label – “one-quarter of the recommended dose” – whatever THAT means. Often, those recommendations are coming from producers who don’t know anything about what you’re growing or how you’re growing it, or provide misleading information on their labels, and whose goal is to sell fertilizer, not grow plants!
Well, fear not, as this Nitrogen Mixing Calculator will provide all of that, for any fertilizer.