You can safely use the Length Conversion Page to convert to and from inches of rain and millimeters of rain.

It is true that rainfall fall is measured differently, but it all works out to just a plain old height measurement. But I know you would never be happy with the simple explanation, so then, let us work this problem out using our good friend, math.

Rainfall is measured by Volume over an Area. In algebra terms that is Volume/Area.

Volume = Length * Width * Height
Area = Length * Width

Now we know rainfall is measured by Volume/Area, we can substitute.

Volume/Area
(Length * Width) * Height / (Length * Width)
And since the common terms cancel each other out, we are left with just Height.

Maybe I overly complicated the matter, so in the simplest terms, just consider inches of rain as inches, and millimeters of rain as millimeters, and convert them as usual.

Visit the Length Conversion Page

 
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