Hi Nan, The forumla for computing ideal body composition from Protein Power starts on page 63. [paperback edition of the original PP book] This is in the chapter of the book called "Assessing Your Risk." It is a rather involved mathematical formula and you will need a tape measure so you can measure, record and then calculate body composition. I am not talented enough at math to put the formula into my own words! But in simple terms, you will need to measure your wrist, hips, waist and then follow the directions and charts in the chapter to find your goal numbers. It is kind of fun to do and it is a different way of looking at things. At 5'1" you are probably in the right ballpark as far as your present goal estimate. Looking forward to hearing about your progress.