You can estimate your body-fat percentage with nothing more than a tape measure. The US Navy method uses your height, neck and waist, plus hips for women. A body-fat level of 14–24% for men and 21–31% for women covers the fitness and average categories; 25% or more in men and 32% or more in women is classed as obese.
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Men: 495 ÷ (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450
Women: 495 ÷ (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.22100 × log10(height)) − 450
All measurements in centimetres
The method works because waist size tracks body fat while neck size and height track lean frame. Measure the neck just below the Adam’s apple. Men measure the waist at the navel; women at the narrowest point, and the hips at the widest point. Keep the tape level and snug without compressing the skin, and measure relaxed, not sucked in.
A man who is 170 cm tall with a 38 cm neck and an 85 cm waist comes out at 17.8% body fat. A woman who is 160 cm tall with a 32 cm neck, 75 cm waist and 96 cm hips comes out at 29.3%.
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Obese | 25% and above | 32% and above |
Categories from the American Council on Exercise (ACE).
A tape-measure estimate can be off by a few percentage points for any one person, so the trend matters more than the number. Measure at the same time of day, in the same way, every two to four weeks. If your weight is steady but your waist is shrinking, you are losing fat and gaining muscle, which the scale alone would never show you.
Coach Himanshu is a NASM-certified fitness coach. About the coach
For men, 14–17% is the fitness range and 18–24% is average; for women, 21–24% is the fitness range and 25–31% is average. Athletes often sit lower. Body fat of 25% or more in men and 32% or more in women is classed as obese on the American Council on Exercise scale.
It estimates body fat from circumference measurements. For men it uses height, neck and waist; for women, height, neck, waist and hips. A larger waist relative to the neck and height indicates more body fat. The equations were developed by Hodgdon and Beckett at the US Naval Health Research Center in 1984.
It is a reasonable estimate rather than a precise measurement, and for an individual it can differ from a DEXA scan by a few percentage points. Its strength is repeatability: measured the same way each time, it tracks change reliably, and it needs no equipment beyond a tape.
Measure the neck just below the Adam’s apple with the tape sloping slightly down at the front. Men measure the waist at navel level; women at the narrowest point of the torso. Women measure hips at the widest point of the buttocks. Stand relaxed, keep the tape level and snug but not tight, and take each measurement twice.
Body-fat percentage tells you more, because it separates fat from muscle, which BMI cannot. BMI is quicker and good for a first screen. Use both: BMI and waist to check health risk, and body-fat percentage to track whether the weight you gain or lose is fat or muscle.
A calculator gives you a target. Coach Himanshu builds the workout and Indian diet plan that gets you there, and adjusts it as your body changes.