How to Express PPM in Percentage

Chemists have a variety of means with which to describe the concentration of chemicals in solutions. A common method is to use parts per million (ppm), which is the "parts" -- such as grams -- of chemical per one million equivalent parts of solution. Another method is to use weight percent, which is the grams of chemical in 100 grams of solution. Because these two ways of describing concentration are based on similar concepts, you can convert readily from ppm to percentage using a basic conversion formula.

Things You'll Need

• Calculator

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Instructions

1. • 1

     Enter your numerical value of concentration, in units of ppm, into the calculator. For example, if you are converting a value of 300 ppm, you will enter 300.

   • 2

     Divide the value you just entered by 10,000. This is the conversion factor between ppm and percent by weight.

   • 3

     Report the result of your calculation as the concentration of the solution, in units of percent by weight. In the case of the example, you would divide 300 by 10,000 to obtain a concentration value of 0.03 percent by weight.