I am completely convinced that this value, 18.0182, is actually a mathematical error. If you do 1/18, you get 0.0555555555; if you round that to 0.0555 and invert it again you get 18.018018, and if you invert 18.0182 you get 0.055499.

I think someone just got sloppy and did 1/(round(1/18)) to get that number.

The proper molecular weight of glucose is 180.1559 g/mol. Which would mean that the conversion should technically be 18.01559.

It would be nice to know whether other people in the industry use 18, 18.0182, 18.01559, or what. Is there some way we can find out?