What is Body Fat (%) ?

Body fat percentage is different by age group and sex. National authorities define/provide diversified/ ideal recommendations for them. 

Description Body Fat (%) of Fitness. 
Age Female Male
10~34 20.9%~32.5% 8.6%~19.3%
35~49 23.5%~35.1% 11.8%~22.5%
50~80 24.5%~36.1% 13.8%~24.5%

Reference: Daniel P.Williams, Scott B. Going, Timothy G. Lohman, David W. Harsha, Satharnur R. Srinivasan, Larry S. Webber, Gerald S. Berenson, Body fatness and risk for elevated blood pressure, total cholesterol, and serum lipoproteinrations in children and adoles cents American journal of public health, March 1992 , Vol. 82, No.3.