Body fat percentage is a more meaningful indicator of health and body composition than BMI for most people. Two individuals with the same BMI can have very different body fat percentages — one lean with significant muscle, the other carrying mostly fat. Measuring body fat percentage at home without expensive equipment is possible using the US Navy tape measurement method.
The US Navy Method
The Navy method uses circumference measurements taken at specific body points and a logarithm formula to estimate body fat percentage. While not as accurate as DEXA scan or hydrostatic weighing, it is reliable within 3–5% for most people and requires only a flexible tape measure.
Measurement Points
For men: measure waist circumference at the navel, and neck circumference at the narrowest point below the larynx. For women: measure waist (at narrowest point), hip (at widest point), and neck (same as men). All measurements in centimetres.
Men: Body Fat % = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76 Women: Body Fat % = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387 Example (man): Waist 88cm, Neck 38cm, Height 172cm BF% = 86.010 × log10(88 − 38) − 70.041 × log10(172) + 36.76 = 86.010 × log10(50) − 70.041 × log10(172) + 36.76 = 86.010 × 1.699 − 70.041 × 2.236 + 36.76 = 146.10 − 156.61 + 36.76 = 26.25%
Healthy Body Fat Ranges for South Asian Adults
South Asian bodies tend to accumulate more visceral fat at lower overall body fat percentages than Western populations. The following ranges reflect guidance appropriate for Bangladeshi adults.
Body Fat Percentage Classification — South Asian Adults
| Category | Men | Women |
|---|---|---|
| Essential fat (minimum) | 3 – 5% | 10 – 13% |
| Athletic | 6 – 13% | 14 – 20% |
| Fit | 14 – 20% | 21 – 26% |
| Acceptable | 21 – 25% | 27 – 31% |
| Overweight | 26 – 30% | 32 – 36% |
| Obese | Above 30% | Above 37% |
For South Asian men, a body fat percentage above 23–25% is associated with significantly increased metabolic risk even when BMI appears normal. For women, the corresponding threshold is approximately 30–32%. These are lower than the thresholds commonly cited for Western populations.
Tip
Take measurements at the same time of day, in a relaxed state, before eating. Morning measurements before breakfast give the most consistent results. Tape the measurements consistently — not too tight, not too loose — and take three readings at each site, using the average. A single inconsistent measurement can throw off the result by several percentage points.