About this tool
Estimate body fat percentage from tape-measurements of neck, waist (and hip for women) plus height. Quick and equipment-light, with reasonable accuracy.
Formula
Men: %BF = 86.010·log₁₀(waist − neck) − 70.041·log₁₀(height) + 36.76. Women: %BF = 163.205·log₁₀(waist + hip − neck) − 97.684·log₁₀(height) − 78.387. (All measurements in inches.)
Worked example
Male, 175 cm, 85 cm waist, 38 cm neck → ~17.4% body fat.
Notes
Accuracy is ±3% compared to DEXA scans. Measure waist at the navel, neck below the larynx, hip at widest point. Stand relaxed without sucking in.