How big will this dog get?

I recently got a shelter dog. I posted pics on y/a and asked a rescue worker what breed they thought he was. The most often guess was husky / border collie mix. He is one years old approximately. He is really malnourished and scrawny. We are working on that with high protein food. I am curious how much taller he will become. When do they stop getting taller. He does have big paws and head. Right now he is about twenty inches to top of front shoulder.