Estimate Your Body Fat with Just a Tape Measure
Enter your height, neck, waist, and hip measurements to get your body fat percentage, lean mass breakdown, and a combined health score using the U.S. Navy circumference method.
Calculate Body Fat
Body Fat Calculator
Estimate body fat and lean mass with the U.S. Navy Method. Enter neck, waist, and hip measurements to see your composition breakdown.
Gender
Unit System
Measurements
Exercise Frequency
3 days / weekEnter your measurements to see your body composition analysis
The U.S. Navy Method is an estimate with an error margin of about 3-4%. Consult a healthcare professional for a clinical assessment.
U.S. Navy Circumference Method
The calculator uses the U.S. Navy body fat formula, which derives fat percentage from height, neck, and waist circumference for men, and adds hip circumference for women. It is more accurate than BMI at estimating actual body composition.
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Body Fat and Lean Mass Charts
Results appear instantly as two doughnut charts. The first shows your body fat percentage alongside your lean mass percentage. The second shows your composite health score, which blends body fat, BMI, and exercise frequency into a single 0-100 rating.
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Metric and Imperial, Male and Female
Switch between metric (kg and cm) and imperial (lb and inches) with one tap. The calculator automatically adjusts defaults and shows the hip measurement field for female users, since the Navy formula requires it for women.
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Choose gender and units
Select male or female and pick metric or imperial. The form fills in sensible defaults and shows the hip field for female users.
Enter your measurements
Input your height, weight (used for health score only), neck circumference, waist circumference, and hip circumference if female. Measurements update the result automatically.
Read your results
See your body fat percentage and category in the first chart, then your composite health score in the second. Drag the exercise frequency slider to see how activity level affects the score.
Deep Dive
How the Calculator Works
The U.S. Navy Method uses circumference measurements and height to estimate body fat percentage without requiring special equipment beyond a flexible tape measure.
What This Calculator Offers
Tape Measure Only
No special equipment needed. Any flexible measuring tape is enough.
Fat vs. Lean Charts
Two doughnut charts show body fat, lean mass, and a composite health score.
Gender-Specific Formula
Women include hip measurement; the Navy formula applies different coefficients.
Exercise Factor
Slide to your workout frequency and watch the health score update instantly.
Who Uses It
Who Uses This Calculator
Anyone who wants a more accurate picture of body composition than weight or BMI alone provides.
Frequently Asked Questions
What measurements does the calculator need?
For men: height, weight (for health score only), neck circumference, and waist circumference. For women: all of the above plus hip circumference. All can be entered in either metric (cm, kg) or imperial (inches, lb).
How accurate is the Navy Method?
The U.S. Navy circumference method has an estimated error margin of about 3-4%. It is more accurate than BMI at reflecting body composition but less precise than clinical methods such as DEXA scans (error 1-2%) or hydrostatic weighing (error 2-3%). Its main advantage is that it requires only a flexible tape measure.
What is considered a healthy body fat percentage?
For men, 6-13% is athletic, 14-17% is fitness level, and 18-24% is average for the general population. For women, 14-20% is athletic, 21-24% is fitness level, and 25-31% is average. Essential fat (minimum for basic physiological function) is 2-5% for men and 10-13% for women.
How should I take the measurements for accurate results?
Neck: measure at the narrowest point just below the Adam's apple, perpendicular to the neck. Waist: measure at navel level while standing relaxed, at the end of a normal exhale. Hip (women): measure at the widest point around the buttocks. Keep the tape snug but not compressing the skin, and take each measurement at the same time of day.
How often should I remeasure?
For most people, remeasuring every 4-6 weeks is sufficient. Body composition changes gradually, and measuring more frequently can produce misleading results due to normal daily fluctuations in hydration and posture. Consistency in technique and time of day matters more than measurement frequency.
Why is weight needed if it is not in the body fat formula?
Weight is used only to calculate your BMI, which feeds into the composite health score alongside body fat percentage and exercise frequency. It is not part of the U.S. Navy circumference formula for body fat itself.
Ready to Check Your Body Composition?
Enter your measurements to get your body fat percentage, lean mass breakdown, and health score in seconds.