Body Fat Calculator
Calculate your body fat percentage with our free calculator. Use the accurate US Navy method with body measurements or the quick BMI-based estimation. See your body fat category, fat mass vs lean mass, and healthy ranges for your gender.
Measure at navel level
- Neck Measurement: Measure at the narrowest point, below the Adam's apple. Keep tape snug but not tight.
- Waist Measurement: Men: Measure at navel (belly button) level. Stand relaxed, don't suck in.
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How to Use
- 1 Choose calculation method — Select US Navy Method for more accuracy using body measurements, or BMI-Based Estimate for a quick approximation.
- 2 Enter your measurements — For Navy method: measure neck, waist, and hip (women only). For BMI method: enter height, weight, and age.
- 3 View your results — See your body fat percentage, category (Athletes/Fitness/Average/Obese), fat mass and lean mass breakdown.
- 4 Understand your category — Your result is categorized based on health guidelines specific to your gender. Check the healthy range displayed.
Frequently Asked Questions
How accurate is the US Navy method?
The US Navy method is accurate within ±3-4% for most people when measurements are taken correctly. It's used by the US military for fitness assessments and is one of the most reliable methods that doesn't require special equipment like calipers or DEXA scans.
What's a healthy body fat percentage?
For men: Athletes 6-13%, Fitness 14-17%, Average 18-24%, Obese 25%+. For women: Athletes 14-20%, Fitness 21-24%, Average 25-31%, Obese 32%+. Women naturally carry more essential fat for reproductive health.
Why is body fat percentage better than BMI?
BMI only considers height and weight, not body composition. A muscular person might have a high BMI but low body fat. Body fat percentage directly measures fat vs lean mass, providing a more accurate picture of health and fitness level.
How do I measure correctly for the Navy method?
Use a flexible measuring tape. Neck: measure at the narrowest point below Adam's apple. Waist: men measure at navel, women at narrowest point. Hip (women): measure at widest point including buttocks. Take 2-3 measurements and average them for best accuracy.
Is my data private and secure?
Yes! All calculations happen entirely in your browser. Your measurements and results are never sent to any server. There's no tracking, no accounts, and no data collection.