When making tree rings, how do you judge the circumference? I want to come up with a formula for cutting these things that I can refer to when bidding etc. For example, would a 2" caliper tree get a 6' diameter tree ring? Does it depend upon the species planted? If there's not a standard, I want to make my own. I don't want to eye-ball it, or have my helper use his judgement and after the job have a tree ring that just don't look right. What do you scapers do in this situation? Bill Craig!