When I was little, all airlines published their flight schedules in little booklets, which were distributed at their airline offices. Nowadays, only PDF versions of these exist, but they are a great tool for checking the official mileage provided between city pairs.

Air Canada has theirs on its website: (download the timetable PDF)
However, when I downloaded the PDF, it was filled with blank pages. Might just be on my computer having this error.
http://www.aircanada.com/en/travelin...les/index.html

However, Star Alliance has its own version too for all member airlines (PDF format):
http://www.staralliance.com/en/servi...ds/timetables/