I was involved with metric on a job. It was fiber optic cable written in meters not inches or feet. I had several thousand feet I measured out for 50 some odd runs anywhere between 75' to 900'. Use the greenlee measuring tape wriiten in feet. After all the measurements were descibed on paper where each run goes. The fiber optic was ordered in Dozens of rolls, all in metric. At that moment I didn't know which one was for what. Thank God one of the helpers says, Hey! I have a metric conversion calculator in my truck. The kid saved the day, I didn't know the conversions off the top of my head. By the way just in case anyone was wondering, it was for a multiple complex installing security cameras.