How to convert number in parts-per million (ppm) to percent (%).
ppm to percent conversion
1% = 1/100
1ppm = 1/1000000
So one parts-per million is equal to 0.0001 percent:
1ppm = 0.0001%
So to convert from ppm to percent, divide the ppm by 10000:
x(%) = x(ppm) / 10000
Example
Convert 300ppm to percent:
x(%) = 300ppm / 10000 = 0.03%