There is an machine out called the bodygem and you breath into it and it tells you your metabolic rate. Now it costs a fortune, but I guess some gyms and doctors have them. This site helps you locate them. I don't don't what the gyms would require (membership?) to use it, but I found a dietician in my area. I think I'll give him a call. Wouldn't it be cool to know your exact rate. We are always talking about how do I find out how many calories we need!