The body fat percentage is commonly calculated from one of two formulas (ρ represents density in g/cm3):* Brozek formula: BF = (4.57/ρ − 4.142) × 100* Siri formula is: BF = (4.95/ρ − 4.50) × 100===Bioelectrical impedance analysis===The bioelectrical impedance analysis (BIA) method is a lower-cost (from less than one to several hundred US dollars in 2006) but less accurate way to estimate body fat percentage.