I presume you probably have a pair of calipers somewhere you could borrow? Well here's my process for chainline tuning...

Measure the following things:
Tcr (thickness of chainring)
Tcg (thickness of cog)
Df (Distance between left side of seat tube and outside face of chainring)
Dr (Distance between inside face of right dropout and outside face of cog)
ODst (Width of seat tube = outside diameter of seatpost)
Wd (Width between inside faces of both dropouts)

chainline_rear = Wd/2 - Dr - Tcg/2
chainline_front = Df - ODst/2 - Tcr/2
compare

buy the right width bottom bracket spacer(s) if the front chainline is less than the rear chainline, if its the other way, flip the chainring to the inside of the cranks and then buy the necessary spacer...

Much simpler than it sounds.
jon