Body fat calculator

All you need is a tape measure. Enter your height and a few circumferences to estimate your body fat percentage, fat mass and lean mass.

ft
in
lb
in

Just below the larynx.

in

Men: at the navel. Women: narrowest point.

in

Widest point of the hips.

Estimated body fat
16.5 %
Fitness
Fat mass
29.7 lb
Lean mass
150.3 lb
Category
Fitness
Body composition
Lean mass150.3 lb84%
Fat mass29.7 lb17%
Body fat categories for men (American Council on Exercise)
CategoryBody fat
Essential fat0–5%
Athletes6–13%
Fitness14–17%
Average18–24%
Obese25%+
  • The Navy method is typically within about 3–4 percentage points of lab methods like DEXA. Measure at the same time of day for tracking.

How to measure

  • Neck: just below the Adam's apple, tape sloping slightly down to the front.
  • Waist: men at the navel; women at the narrowest point. Relax and don't suck in.
  • Hips (women): around the widest part of the buttocks.

Keep the tape snug but not compressing the skin, and take each measurement twice.

The U.S. Navy formula

Developed by Hodgdon and Beckett for the U.S. Navy, it estimates body fat from circumferences and height using logarithms. It's free and repeatable, which makes it great for tracking changes, though less precise than a DEXA scan.

What's a healthy body fat percentage?

For general health, roughly 10–20% for men and 18–28% for women is a common range. Very low levels below the "essential fat" line aren't healthy to sustain.

Frequently asked questions

How accurate is the Navy body fat method?
Usually within 3–4 percentage points of DEXA for most people. It's less accurate for very lean or very muscular people, but consistent enough to track trends.
Why do women need a hip measurement?
Women tend to store more fat on the hips and thighs, so the female equation adds hip circumference for a better estimate.
How often should I measure?
Every 2–4 weeks is enough. Measure at the same time of day, ideally in the morning before eating.

These results are estimates for healthy adults and are not medical advice. If you are pregnant, breastfeeding, under 18, or managing a medical condition, talk to your doctor or a registered dietitian.

Related calculators

FFMI calculator
Fat-free mass index: how muscular you are for your height.
Lean body mass calculator
Estimate lean body mass from height and weight, or from body fat.
BMI calculator
Body mass index, weight category and healthy weight range for your height.