# Fertilizer ratios



## bandwgn09 (Aug 8, 2017)

So I know when I fertilize I should use 1 lb of nitrogen for every 1k square ft of grass. But of course the fertilizer bags are not pure nitrogen. How many pounds of fertilizer equals 1 pound of nitrogen?
If the ratio in the bag is 24-2-4 how many lbs of fertilizer for 1 lb of nitrogen. What if the ratio is 15-15-15 or 32-0-0?
thank you


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## Spammage (Apr 30, 2017)

@bandwgn09 the first number is the nitrogen. 24 means that 24% of the product is nitrogen, so you would apply 4 lbs of that fertilizer to get 1 lb of nitrogen.


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## dfw_pilot (Jan 28, 2017)

Spammage is right. Here are the formulas.


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## Movingshrub (Jun 12, 2017)

Spammage said:


> bandwgn09 the first number is the nitrogen. 24 means that 24% of the product is nitrogen, so you would apply 4 lbs of that fertilizer to get 1 lb of nitrogen.


I take the approach of 100/the percentage of nitrogen on the bag = the amount of pounds of that product per 1,000 sqft I need to get one pound of N per 1,000 sqft.

15-15-15 = 100/15 = 6.67lb of product per 1k sqft
10-10-10 = 100/10 = 10lb of product
34-0-0 = 100/34 = 2/94lb of product, and so on.


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## bandwgn09 (Aug 8, 2017)

Math in real life!! Thanks guys.


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