Body Fat % Calculator (US Navy Method)
Enter your measurements below to estimate body fat percentage and compare your result with a healthy range for your age and sex.
What is a healthy body fat percentage?
A healthy body fat percentage is the amount of fat your body carries while still supporting good hormone function, energy, and long-term health. Unlike body weight alone, body fat percentage helps you understand body composition—how much of you is fat mass versus lean mass (muscle, bone, organs, water).
This matters because two people can weigh the same and have very different health profiles. One might carry more muscle and less fat, while the other may carry more body fat and less lean tissue.
Healthy body fat ranges by age and sex
Different organizations publish slightly different ranges. The table below is a practical guideline for adults and is what this calculator uses to label your result as below, within, or above the healthy range.
| Age | Men: Healthy Range | Women: Healthy Range |
|---|---|---|
| 20–39 | 8%–19% | 21%–32% |
| 40–59 | 11%–21% | 23%–33% |
| 60–79 | 13%–24% | 24%–35% |
How this calculator works
This tool uses the U.S. Navy body fat formula. It estimates body fat from circumference measurements:
- Men: height, neck, and waist.
- Women: height, neck, waist, and hips.
It is quick, inexpensive, and generally more informative than BMI alone. However, it is still an estimate—not a direct scan like DEXA.
Accuracy tips
- Measure with a flexible tape on bare skin or thin clothing.
- Keep tape snug but not tight (don’t compress skin).
- Measure at the same time of day, ideally morning.
- Take 2–3 readings and use the average.
- Track trends over weeks, not day-to-day noise.
How to interpret your result
Your result includes three useful layers:
- Estimated body fat percentage (the main number).
- Body fat category (essential fat, fitness, average, etc.).
- Healthy range status for your age and sex.
If your number is above the healthy range, focus on gradual fat loss while preserving muscle. If below range, especially with fatigue or hormonal symptoms, talk with a healthcare professional.
Ways to improve body composition safely
1) Prioritize resistance training
Lift weights or perform resistance exercise at least 2–4 times per week. Building muscle supports metabolism and helps prevent “skinny fat” outcomes.
2) Keep protein intake consistent
Protein supports muscle retention during fat loss and recovery after training. Include a protein source in each meal.
3) Use moderate calorie changes
Extreme diets are hard to sustain and can reduce lean mass. A moderate calorie deficit is usually more effective long-term.
4) Sleep and stress matter
Chronic poor sleep and high stress can make fat loss harder and influence hunger hormones. Aim for regular sleep and stress-management habits.
Body fat percentage vs. BMI: which is better?
BMI is useful for population-level screening, but it does not separate fat from muscle. Body fat percentage gives a clearer individual picture, especially for muscular people, active adults, and anyone recomping (losing fat while gaining or maintaining muscle).
Frequently asked questions
Is this calculator suitable for everyone?
It is designed for adults. It may be less accurate for highly trained athletes, pregnant individuals, or people with unusual fat distribution.
How often should I check body fat?
Every 2–4 weeks is usually enough. Daily checks are unnecessary and can be misleading due to normal fluctuation.
Can I lower body fat without losing weight?
Yes. Recomposition is possible—especially for beginners and returning trainees—through strength training, adequate protein, and good recovery.
Bottom line
A healthy body fat percentage offers more meaningful insight than scale weight alone. Use this calculator to estimate your current level, compare it against a healthy range, and monitor progress over time. For personalized targets—especially if you have medical conditions—consult a qualified healthcare professional.