Manuela, I know you have been suggested a lot of things to help you in your quest to get your fat percentage. I went to and bought one of the "Digital Fat Tracker 11" calipers about 2 years ago and it has been accurate within 2%...I take the measurements myself and it is really easy..Just go to and click on "Training" then scroll down to "Tracking Progress" and click on "Measuring Body Fat"....then click on "Composition 411" now use the body mass index to see what your "BMI" is ( this is an estimate only, but close) then scroll down and read Article on "Calipers" and other way's of measuring "Body Fat"...Manuela I have found that Christopher Mohr is one of the most respected men in our business and is well informed on our BFL program. I believe in "Researching" things not just taking everyone else's advice..It does not mean they are not right it just means "what may work for them may not work for you or I"...So may I suggest you "Research"...If you need help please let me know. John