# Parts per million

How do you calculate parts per million (or billion) from grams and volume?

I ask this in relation to figureing out how to translate water report information into the recommended ranges of certain brewing salts for emulating water profiles.

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This answer will undoubtedly involve mols. /gets out the popcorn and chemistry text book – tbeseda Mar 5 '10 at 16:47

Actually its moles free, so no chemistry text or periodic table needed. I just looked it up and did the math.

1ppm means one part in one million parts.

For instance then. 1 milligram in 1 kilogram. (1kg=1000g=1,000,000mg)

The more relavant application for brewing would be mg of solid (CaCl2) in a liter of water. Its tricky because first you need to assume that 1 gram=1milliliter of water.

So 1 ppm is 1mg/Liter via the following:

1mg=0.001ml 1L=1000mL

0.001/1000 = 1/1,000,000 or 1ppm

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Though, I don't know the actual math (and disappointed that it doesn't involve calculating molarity), I did find this calculator to be helpful (if not saturated with Google ads).

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