Body Fat Calculator
Calculate your body fat percentage using the clinically validated US Navy formula. This tool estimates your body fat based on circumference measurements—neck, waist, and hip (for females)—along with your height, weight, and age. Perfect for tracking fitness progress and understanding your body composition.
How to Use This Tool
1. Select Gender
Male or Female
2. Enter Age
Years
3. Enter Height & Weight
Choose units
4. Enter Measurements
Neck, waist, hip
5. Get Results
View body fat %
Formula & Calculation
Results are rounded to 1 decimal place for clarity.
Quick Reference Body Fat Table
| Category | Male (%) | Female (%) | Health Status |
|---|---|---|---|
| Essential Fat | 2–5 | 10–13 | Minimum required |
| Athletes | 6–13 | 14–20 | Excellent fitness |
| Fitness | 14–17 | 21–24 | Good fitness |
| Average | 18–24 | 25–31 | Moderate health |
| Obese | 25+ | 32+ | Increased health risk |
How We Calculated
- Input: We collected your gender, age, height, weight, neck, waist, and hip (females).
- Conversion: Height is converted to inches, weight to kg for BMI calculation.
- Formula: Applied the US Navy formula (gender-specific) to estimate body density.
- Result: Body density is converted to body fat percentage using the Siri equation.
Why Trust This Tool?
Clinically validated method
No server storage
Use instantly
Works on all devices
Latest fitness insights
No hidden charges
Accuracy & Standards
This calculator uses the US Navy formula, one of the most widely validated circumference-based methods for estimating body fat percentage. Results are rounded to 1 decimal place. The tool is for educational and fitness tracking purposes—not a substitute for professional medical advice.
Unit Relationship
1 kg = 2.20462 lbs
1 cm = 0.393701 in
1 lb = 0.453592 kg
1 in = 2.54 cm
Learn About Body Fat
What is Body Fat Percentage?
Body fat percentage is the proportion of fat mass to total body weight. It's a better indicator of health than BMI, as it distinguishes between fat and muscle mass.
Why It Matters
Higher body fat is linked to increased risk of chronic diseases like diabetes, heart disease, and hypertension. Maintaining a healthy body fat percentage supports overall health and longevity.
Body Fat vs BMI
BMI only considers height and weight, while body fat percentage accounts for body composition. Two people with the same BMI can have very different health risks based on their body fat percentage.
Real-World Examples
- Example 1: Male, 30yo, 70kg, 175cm, Neck 15in, Waist 32in → Body Fat: 15.2% (Fitness)
- Example 2: Female, 35yo, 65kg, 165cm, Neck 12in, Waist 28in, Hip 38in → Body Fat: 26.5% (Average)
- Example 3: Male, 40yo, 85kg, 180cm, Neck 16in, Waist 38in → Body Fat: 22.8% (Average)
Limitations of This Tool
- Requires accurate circumference measurements for best results.
- May not be accurate for very muscular individuals or pregnant women.
- Does not account for differences in bone density or muscle distribution.
- For more precise measurement, consider DEXA scans or hydrostatic weighing.
Trust & Privacy
We take your privacy seriously. This tool:
- Does not store data on any server
- All calculations happen locally in your browser
- No cookies are used for this tool
References
- U.S. Navy. Body Fat Estimation Formula. Navy Medicine Institute.
- American Council on Exercise. Body Composition Testing. ACE Fitness.
- National Institutes of Health. Body Composition and Health. NIH.gov.
Editorial Process
The Healthtus editorial team, consisting of fitness experts and certified nutritionists, reviews this tool regularly to ensure accuracy and alignment with the latest exercise science. We update the content and references as new research emerges.
Last reviewed: July 2026