NOTICE: While the information generated from this site is believed to be accurate, any actions taken based upon the results are the sole responsibility of the user.

This calculator computes the pounds of a given fertilizer required, based on the nutrient ratio of the fertilizer (the three numbers prominently displayed on the fertilizer label, sometimes called the "N-P-K ratio") and the pounds of nitrogen (N), phosphate (P2O5), and potash (K2O) necessary for a given area, as stated in a reliable soil test.

To use this calculator, you must enter the percentages of nitrogen, phoshpate, and potash in the fertilizer you are using. These percentages are the three numbers which appear on the fertilizer package. Do not enter the symbol "%".

You must also enter the pounds of nitrogen, phosphate, and potash required, as indicated by a soil test. This test will give the number of pounds of each of these nutrients per a certain area (for instance, per 100 square feet). You must also enter this area.

Finally you must enter the area of your lawn or garden.

Fill in the fields, then click on calculate:

Percent Nitrogen in fertilizer:
Percent Phosphorus in fertilizer:
Percent Potassium in fertilizer:
Given area on the soil test:
Pounds of Nitrogen per given area:
Pounds of Phosphorus per given area:
Pounds of Potassium per given area:
Area to be fertilized:

The number of pounds of fertlizer required is .

This page was last revised on December 4, 2004.

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