Use a body fat scale or smart scale
Use skinfold calipers at multiple body sites
Use the U.S. Navy method with measurements
Use BMI-based estimation formulas
Use bioelectrical impedance analysis
Use DEXA scan for the most accurate estimate
Use hydrostatic weighing
Use air displacement plethysmography
Measure weight, height, waist, neck, and hip if required by the formula
Apply the selected formula or device reading to get the percentage
Track the same method consistently for comparison over time