There is a lot of measurement involved in brewing coffee: the weight of the grinds, temperature of the water, etc. But as far as I can tell, there is no standardization on the size of the grinds. Recipes usually call for hand wavvy sizes like "set the grinder midway between drip and espresso grind" (for an Aeropress). Even an approximate standard would be more useful.  I'm curious if there is a standard unit of measure for grind size? If there is, do grinder manufacturers use or publish this information? 
Take a look at this link from Coffee Chemistry, it's not a standard, per se, but it provides useful information.  Table from article:  