That is a question that every one asks, even myself, and everyone usually gets the same answer... All tortoises grow differently. There really isnt a chart of how big a tortoise should be at a certain age. If you post how old your tortoise is and how much it weighs, some people will give you input on what they think and how much theirs weighed at that age. Sometimes that helps...
My 7 month sulcata, Little Ricky has a thread with his weights that I'm updating somewhat regular. The title is something along the lines of “Little Ricky's official growth chart thread" he a good example of Little Ricky's growth.