Hi, if you go to the Settings folder in the Workout Manager, you can change lbs to kgs with one click (it was truly frustrating having to convert every workout card to kgs. On day, I was playing around the WM and stumbled on to the settings page; and voilà, life is so much easier. I was so excited to start STS I didn't bother to check to see if it was even possible. Cathe thought of everything!) Hope this helps
All that's needed really is to be able to work with half kilos, the same degree of accuracy as whole pounds.
We've now made it so the 1RM calculator will show the fraction weight for metric users. We're still working on finishing this for workout calendar cards.