Body Fat Calculator: Estimate Body Fat % by Height, Weight, Age & Gender
Body Fat Calculator
Two people can share the same BMI while having completely different health profiles — one may be muscular, the other carrying excess fat. Body fat percentage reflects actual body composition far better than BMI alone.
Body Fat Calculator (Navy Method)
Navy Method
Measure neck, waist, and hip circumferences for an accurate body fat estimate.
Body Fat %
21.8%
Acceptable
Fat Mass
15.3 kg
Lean Mass
54.7 kg
Ideal Weight Range
56.7 — 76.3 kg
Body Fat Percentage Reference Chart
| Classification | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Acceptable | 18–24% | 25–31% |
| Overweight | 25–30% | 32–37% |
| Obese | 31%+ | 38%+ |
Body fat % vs. BMI: BMI only considers height and weight. Body fat percentage measures actual fat ratio. A muscular athlete may have a BMI above 25 (classified “overweight”) while their body fat is below 12%.
Calculation Method (U.S. Navy Formula)
This calculator uses the U.S. Navy body fat formula, the most accurate measurement approach that doesn’t require special equipment.
Men: 86.01 × log10(waist − neck) − 70.041 × log10(height) + 36.76
Women: 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387
Body Fat Reduction Strategy
| Goal | Strategy |
|---|---|
| Lose 1 kg of fat | ~7,700 kcal deficit (~500 kcal/day × 15 days) |
| Minimize muscle loss | 1.6–2.2 g protein per kg of body weight |
| Combine cardio + strength | Strength training preserves basal metabolic rate |
| Healthy pace | 0.5–1% reduction per week |
OIYO Editorial
Editorial DeskThe OIYO editorial desk researches money, law, lifestyle, and self-understanding topics against primary sources and public statistics. Every piece carries source notes and is reviewed on a regular cycle for accuracy and usefulness.