low bridges

I know that my "C" is less than 12 feet because I drive it through a 12' x 12' door in my storage building. Driving thru Canada on my way to Alaska, MPH and KPH are marked on the speedometer, so I was good to go - until I was facing a bridge in downtown Calgary one morning. The clearance on the sign said "5 meters". Not wanting to drive to Alaska in a Class C convertible, I pulled over. Checked my trusty homemade cheat sheet that said a meter was 3 feet and change, so I drove through. But the one that stumped me in a grocery store was buying lunch meat sold by the gram. I didn't have a clue, so I ordered 8 slices. And I still don't know the answer to that one.