Body Fat Calculator
Estimate body fat percentage using the U.S. Navy Method (no equipment needed beyond a measuring tape).
What is body fat percentage?
Body fat percentage estimates how much of your body weight is fat mass compared with lean mass. Unlike BMI, body fat percentage aims to reflect body composition more directly, but it still depends on measurement accuracy and the method used.
U.S. Navy method explained
The U.S. Navy method estimates body fat using circumference measurements (height, neck, waist, and for women, hips). It uses a base-10 logarithm formula and is popular because it’s fast and requires only a tape measure.
Body fat categories for men and women
Men
- Essential fat: 2–5%
- Athletes: 6–13%
- Fitness: 14–17%
- Average: 18–24%
- Obese: 25%+
Women
- Essential fat: 10–13%
- Athletes: 14–20%
- Fitness: 21–24%
- Average: 25–31%
- Obese: 32%+
Frequently Asked Questions
Quick answers about body fat estimation.
How is body fat calculated?
This calculator uses the U.S. Navy circumference method with a base-10 logarithm formula.
What is a healthy body fat percentage?
Healthy ranges vary by gender and age. The Fitness/Athletes categories are often considered healthy for active adults.
Is the Navy method accurate?
It’s a useful estimate, but accuracy depends on tape-measure technique and individual body shape.
How do I measure waist and neck?
Measure neck below Adam’s apple. Measure waist at the narrowest point (or at the navel if unsure). Keep the tape snug, not tight.
Is BMI better than body fat percentage?
BMI is simpler but doesn’t reflect body composition. Body fat percentage can be more informative when measured accurately.
Disclaimer
This tool provides an estimate for informational purposes only and does not provide medical advice. For personalized guidance, consult a qualified professional.