I did a quick Excel spreadsheet of the MC18 gearing.
You can alter the sprocket teeth and rear wheel circumference (the blue cells in the spreadsheet) to suit what you have, to see what you'll get.

For what its worth, I like to use 16 tooth front and 42 tooth rear for the road.
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[color=#808080][size=9]Yes,.. I too know how to waste Time and Money,...