Body Fat Percentage Calculator

Understanding Body Fat Percentage

Body fat percentage estimates how much of your total weight is fat mass. It is different from BMI because it focuses on body composition rather than weight alone. This calculator uses a tape-measure method similar to the U.S. Navy circumference approach.

How the tape-measure method works

The Navy-style formula uses height, neck, and waist measurements (plus hip measurements for women) to estimate body fat percentage. It is fast and accessible, but it is still an estimate and not a direct measurement like DEXA or hydrostatic weighing.

Typical adult categories

Category ranges vary by organization. The labels used here align with common fitness ranges (similar to ACE) and are shown by sex:

• Men: Essential < 6%, Athletic 6–13%, Fit 14–17%, Acceptable 18–24%, High 25%+
• Women: Essential < 14%, Athletic 14–20%, Fit 21–24%, Acceptable 25–31%, High 32%+

Tips for consistent measurements

• Measure at the same time of day, ideally before eating.
• Use a flexible tape and keep it level without compressing the skin.
• Take each measurement twice and use the average.

Important limitations

• Results can shift with hydration, posture, or measurement placement.
• Formulas are less accurate for very muscular people, older adults, or during pregnancy.
• Body fat percentage is only one health indicator; consult a professional for guidance.

Sources

• U.S. Navy body fat circumference method (formula reference)
• American Council on Exercise (ACE) body fat percentage categories