Here is a simple explanation from Schwalbe and the confusion that people are making.

Please note that in the example it's a 37-622 rating on a 700x35c tyre and that tyre will be 37mm wide ± 3 mm when inflated properly.

I think that people in this thread are confusing the two systems.

I suggest that people out their money where their mouth is and actually post measurements like the one already done in this thread.