Body Fat Calculator
Calculate body fat percentage using the US Navy method
Your Measurements
Measure at navel level
Measure at widest point
Enter your measurements and click Calculate
Body Fat Percentage (US Navy Method)
—%
—Fat Mass
— kg
Lean Mass
— kg
Body Fat Categories
How to Use
- Select your Gender.
- Enter Height (cm), Neck circumference (cm), and Waist circumference (cm) — measured at the narrowest point.
- Women: also enter Hip circumference (cm) at the widest point.
- Click Calculate to see body fat %, fat mass (kg), lean mass (kg), and your fitness category.
- Measure all sites in the morning before eating. Take 3 measurements at each site and use the average.
What is Body Fat Percentage?
Body fat percentage (BF%) is the proportion of your total body weight that is fat tissue. Unlike BMI, which uses only height and weight, body fat % distinguishes between fat and lean mass (muscle, bone, water, organs). Two people with the same BMI can have very different body compositions.
US Navy Method
Our calculator uses the US Navy circumference method — one of the most accessible and reasonably accurate field methods (±3–4% vs DEXA scan). It uses body circumference measurements at key sites.
Men: %BF = 495 / (1.0324 − 0.19077 × log₁₀(waist−neck) + 0.15456 × log₁₀(height)) − 450
Women: %BF = 495 / (1.29579 − 0.35004 × log₁₀(waist+hip−neck) + 0.22100 × log₁₀(height)) − 450
Women: %BF = 495 / (1.29579 − 0.35004 × log₁₀(waist+hip−neck) + 0.22100 × log₁₀(height)) − 450
Body Fat Categories (Indian/ACE Standards)
| 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%+ | 32%+ |
More Accurate Alternatives
- DEXA scan: Gold standard, measures bone density and body composition. Available at hospitals (₹2,000–5,000).
- Hydrostatic weighing: Very accurate but expensive and inconvenient.
- Skinfold calipers: 3–7 site measurement — accurate when done by a trained professional.
- BIA scales: Consumer body fat scales — convenient but affected by hydration level (±5% error).
Frequently Asked Questions
The US Navy circumference method has an accuracy of approximately ±3–4% compared to DEXA scans (the gold standard). It's reasonably accurate for most adults and more accessible than lab methods. Accuracy depends on consistent measurement technique — always measure at the same time of day (morning before eating is best) and use a flexible tape measure, not a rigid ruler.
For men: measure at the level of the navel (belly button). For women: measure at the narrowest point of the torso (usually 1–2 inches above the navel). Don't suck in your stomach — breathe out normally and then measure. Measure 3 times and use the average.
For assessing body composition and health risk, yes. Two people can have the same BMI but very different body fat percentages — a muscular athlete and an overweight sedentary person may both show BMI of 27, but their body fat percentages can differ by 20%. BMI is simpler and sufficient for population screening; body fat % is better for individual fitness assessment.
Indian guidelines recommend slightly lower body fat thresholds than Western standards due to higher metabolic risk at lower fat levels. General targets: Men — 10–20% (fit/normal); Women — 18–28% (fit/normal). Athletes are typically 6–13% (men) and 14–20% (women). Above 25% (men) or 32% (women) is considered obese.