Body Fat Percentage Calculator

The U.S. Navy body fat method uses three tape measurements (neck, waist, and hips) to estimate body fat percentage. It was developed as a practical field test for the military. It is not as precise as a DEXA scan, but it gives a useful estimate without special equipment.

• Military fitness assessments: The Navy formula is used in official U.S. military body composition evaluations.
• Gym progress tracking: Track changes in body composition over time without needing expensive equipment.
• Health screening: Estimate whether body fat percentage falls within healthy ranges for your age and gender.
• Diet and training adjustments: Use body fat percentage alongside weight to tell whether you are losing fat or muscle.

1. 1Select your gender, as the formulas are different.
2. 2Measure your neck just below the larynx (Adam's apple). Keep the tape horizontal.
3. 3Measure your waist: for men, at the navel; for women, at the narrowest point.
4. 4Women also measure hips at the widest point.
5. 5Enter your height in centimeters.
6. 6The calculator applies the Navy formula and shows your estimated body fat percentage and category.

• Measuring waist at the wrong point: The Navy method measures waist at the narrowest point (typically just above the navel for men, at the navel for women). Measuring at the belt line is too low and gives an inaccurate result.
• Sucking in while measuring: Take the waist measurement at the end of a normal exhale, not with your stomach held in. Held-in measurements understate waist circumference and lower the estimated body fat percentage.
• Comparing the result to a DEXA scan directly: The circumference method estimates body fat. DEXA scans measure it directly. A 2-4% difference between methods is normal. Use this calculator for tracking trends, not as an absolute benchmark.
• Measuring over clothing: Tape measurements should be taken directly on skin. Even thin fabric introduces error, especially over multiple measurement points.

• Take three measurements and average: Body measurements vary slightly depending on tape tension and exact position. Take each circumference three times and use the average for each input. This reduces single-measurement noise.
• Measure at the same time of day: Waist circumference increases through the day from food and water. Measure first thing in the morning, before eating or drinking, for the most consistent week-over-week comparison.
• Use it to track trend, not spot-check: Body fat percentage from any field method fluctuates. Track monthly rather than weekly, and look for a 3-month trend rather than reacting to each reading individually.
• Compare with your fitness category, not the chart minimum: Essential fat (the minimum needed for organ function) is 2-5% for men and 10-13% for women. Fitness category (14-17% men, 21-24% women) is a realistic target for most active adults.