Liquid Nitrogen Calculator (Liquid Fertilizer Calculator)

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By: Mark Marino, a Massachusetts Core Applicator License holder
and owner/operator of Lawn Phix,

No AI pledge. Written by Mark, not robots. Learn more.

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  1. Enter the percentage of Nitrogen
  2. Enter the weight of liquid fertilizer per 1 gallon
  3. Enter the amount of Nitrogen you want to apply per 1,000 ft²
    1. e.g. for 3/4 lbs./N, type 0.75


Nitrogen is needed

Weight is needed

Desired N/gallon is needed

More Lawn Care Calculators

This liquid nitrogen fertilizer calculator takes the guesswork out of everything. Simply plug in the nitrogen percentage, weight of the liquid fertilizer, and total pounds of nitrogen you want to apply into our liquid nitrogen calculator, and we will show you exactly how many ounces to apply.

To do the math on calculating the amount of nitrogen in liquid fertilizer, let’s take CoROn 18-3-6 Plus 0.5% as an example. Say I want to spoon feed at 1/2 pound of Nitrogen per 1,000 ft². I plug in 18 in the first box, 10.67 in the second box, and 0.5 in the third box. I click “calculate,” and I get 33.32 ounces. So I now know I need about 1 quart of this fertilizer to get 1/2 pound on N per 1,000 ft². 

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The key to a healthy lawn is first getting a soil test, then applying the fertilizers at the proper rates to ensure that your nitrogen, phosphorus and potassium levels are where they need to be. These macronutrients are the three numbers located on the front of your liquid fertilizer bottles.

Note: you may also use this liquid nitrogen fertilizer calculator for phosphorus and potassium!

Need to calculate granular fertilizer? Check out our original Nitrogen Calculator!

As always – read the label! There may be maximum amounts listed by the manufacturer that may conflict with the output of this calculator.

Here’s a great explanation of the math behind it in this YourTube video:

Author's Note: this piece has been updated for accuracy since its first publication on
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Author: Mark Marino
I am Mark Marino, the founder, owner, and operator of Lawn Phix. With a passion for lawn care and turf nutrition for over a decade, I've dedicated countless hours to correcting soil and perfecting lawns. Today, my expertise, backed by formal courses at UMass Extension Pesticide Education, allows me to offer top-tier services. I am a fully licensed and insured pesticide applicator in Massachusetts, specializing in comprehensive turf nutrition, and weed and pest control. My license number is AL-0053865. Contact me at [email protected] or +1 (508) 500-8402.

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