Your weight on the scale tells you very little about your health. Two people can weigh exactly the same and have completely different body compositions — one lean and muscular, the other carrying excess fat. Body fat percentage is the metric that actually matters for health, fitness, and longevity.
Body fat percentage is the proportion of your total body weight that is fat tissue. The rest — muscles, bones, organs, water — is called lean mass. Knowing your body fat percentage helps you:
| Category | Men | Women |
|---|---|---|
| Essential Fat | 2–5% | 10–13% |
| Athletic | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average / Acceptable | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
Note for Indians: Research shows South Asians tend to carry more visceral (abdominal) fat at lower BMI values. Indian health guidelines often recommend treating 23% BMI as "overweight" and using stricter body fat thresholds.
This method uses a tape measure and is accurate to within 3–4%. It requires measurements in centimetres.
Body Fat % = 495 ÷ (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450
Measurements needed: Waist circumference (at navel), neck circumference, height.
Body Fat % = 495 ÷ (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.22100 × log10(height)) − 450
Measurements needed: Waist (at narrowest point), hip (at widest point), neck, height.
30-year-old man: Height 175 cm, Waist 88 cm, Neck 38 cm
log10(88 − 38) = log10(50) = 1.699
log10(175) = 2.243
Body Fat % = 495 ÷ (1.0324 − 0.19077 × 1.699 + 0.15456 × 2.243) − 450
= 495 ÷ (1.0324 − 0.3241 + 0.3466) − 450
= 495 ÷ 1.0549 − 450 ≈ 19.3%
If you only have your BMI, you can estimate body fat using the Deurenberg formula:
Body Fat % = (1.20 × BMI) + (0.23 × Age) − (10.8 × Sex) − 5.4
(Sex = 1 for male, 0 for female)
This is less accurate than the Navy method but useful as a quick estimate. It tends to underestimate body fat in South Asians.
A trained professional uses calipers to measure the thickness of fat folds at specific sites (usually chest, abdomen, thigh for men; tricep, suprailiac, thigh for women). When done correctly this method is accurate to within 2–3%. It requires a trained assessor and is common in gyms and clinical settings.
A DEXA (Dual-Energy X-ray Absorptiometry) scan is the most accurate way to measure body fat — accurate to within 1–2%. It is available in hospitals and some fitness clinics in major Indian cities. Cost: ₹2,000–₹6,000 per scan. Worth doing once a year if you take body composition seriously.
Body fat percentage is more meaningful for health assessment. BMI cannot distinguish muscle from fat — a muscular person can be classified as "obese" by BMI but have healthy body fat. That said, BMI is easier to calculate without equipment and is useful for population-level screening.
Monthly is sufficient. Daily measurements are noisy due to hydration changes. Track trends over 4–8 weeks rather than day-to-day fluctuations.
Yes — this is called body recomposition. By eating at maintenance calories with high protein and strength training, you can simultaneously lose fat and gain muscle. The scale stays roughly the same but your body composition improves. This is especially common for beginners.
Also see: What is BMR? | Indian Diet Calorie Guide