Matthew I think I may not have explained it as good as I should have. I mark just the mile splits but all the paper work measuring has to be in kilometers. Since I have been doing both I have noticed the kilometer courses are just a little bit longer. I think I am partly to blame because say my pre calibration comes to 17977.1 I will round it up to 17978 counts per mile because I would rather be a little long than end up short. So usually the metric calibration has a lower number after the decimal than the imperial number so than when I round up it does make a difference. If I use the exact calibration number whether metric or imperial I end up with the same number of counts for the entire course distance so the las couple of races I have done I started doing this.