Body Fat Calculator
Estimate your body fat percentage using the proven U.S. Navy method with simple tape measurements.
Body Fat Calculator
Estimate body fat percentage using the U.S. Navy method
Measure at navel level
Measure below larynx
Estimated Body Fat
23.5%
Average
Body Fat Categories
How to Use This Calculator
Select your sex — the Navy method uses different formulas for men and women. Women require an additional hip measurement.
Enter your height, waist, and neck measurements using a flexible tape measure. For women, also measure your hips at the widest point.
The calculator instantly shows your estimated body fat percentage and classifies you into a fitness category from Essential Fat to Obese.
Body Fat vs. BMI
BMI is a screening tool, not a body composition measure. It uses only height and weight, which means a muscular person can be classified as "overweight" despite having low body fat.
Body fat percentage directly measures how much of your weight is fat versus lean mass (muscle, bone, organs, water). This gives a much more accurate picture of your health and fitness level.
Use both metrics together: BMI for a quick screening and body fat percentage for a deeper understanding of your body composition.
Tips for Accurate Measurements
Measure in the morning before eating or drinking, wearing minimal clothing. This gives the most consistent readings over time.
Stand relaxed — don't flex muscles or suck in your stomach. The tape should be level and snug without compressing the skin.
Take each measurement twice and use the average. If the two readings differ by more than 0.5 cm (0.25 inches), measure a third time.
Frequently Asked Questions
What is the U.S. Navy body fat method?
The U.S. Navy method estimates body fat percentage using circumference measurements (waist, neck, and hips for women) along with height. It was developed by the Naval Health Research Center and is used by the U.S. military for fitness assessments. It is reasonably accurate (within 3-4% of DEXA scans for most people).
How accurate is this body fat calculator?
The Navy method is typically accurate within 3-4% of more precise methods like DEXA scans or hydrostatic weighing. It works best for people with average body compositions and may be less accurate for very lean athletes or those with significant obesity.
What is a healthy body fat percentage?
For men, 14-18% is considered the fitness range and 18-25% is average. For women, 21-25% is fitness and 25-32% is average. Essential fat (the minimum for health) is 2-6% for men and 10-14% for women. Athletes typically range 6-14% (men) and 14-21% (women).
How do I measure my waist correctly?
Stand relaxed and wrap a flexible tape measure around your waist at navel (belly button) level. Don't suck in your stomach. The tape should be snug but not compressing the skin. Take two measurements and average them.
Why is body fat percentage better than BMI?
BMI only uses height and weight, so it can't distinguish between muscle and fat. A muscular person may have a "overweight" BMI but low body fat. Body fat percentage directly measures composition, giving a more accurate picture of health and fitness.
How often should I measure body fat?
Measure every 2-4 weeks at the same time of day (morning, before eating). Body fat changes slowly, so measuring more frequently leads to frustration from normal daily fluctuations. Track the trend over months, not individual readings.
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