Body Fat Calculator · Practical guide
How to Measure Body Fat With a Tape Measure
A $2 tape measure and three circumferences are all the Navy method needs — if you measure in the right spots.
At a glance
The Short Version
Wrap a flexible tape around your neck just below the Adam's apple, around your waist at the navel (men) or narrowest point (women), and — for women — around the widest part of your hips. Enter those three or four numbers with your height and weight above, and you get a body fat estimate within about 3 to 4 points of a DEXA scan.
Interactive tool
Body Fat Calculator
Enter your own values, then compare the result with the examples below.
Step-by-Step Tape Placement
- Neck: just below the larynx, with the tape sloping slightly down in front. Keep your neck relaxed — do not flare the muscles.
- Waist (men): horizontally at the navel. Waist (women): at the narrowest point of the torso, usually an inch or two above the navel.
- Hip (women only): around the widest point of the hips and buttocks, feet together.
- Tension: snug and flat against the skin without compressing it. Read the tape at the end of a normal exhale, and do not suck in your stomach.
Mistakes That Skew the Result
Because the formula depends entirely on circumferences, technique is everything. Measure in the morning before eating, record to the nearest quarter inch or half centimeter, and never mix inches and centimeters. A half-inch error at the waist can move the estimate by a full percentage point.
Why Beat the Scale With a Tape?
The scale cannot tell fat from muscle. Two people at 180 pounds can have wildly different health profiles depending on composition. A worked example: a man at 70 inches tall with a 36-inch waist and 15-inch neck measures about 21.3% body fat — Average for men — regardless of what he weighs. Remeasuring every two to four weeks under identical conditions shows real fat-loss progress that the scale alone would hide.
Frequently Asked Questions
Can I measure myself, or do I need help?
You can measure yourself, but a partner improves accuracy — especially for the neck, where arm position changes the reading. If measuring solo, stand in front of a mirror to keep the tape level.
How often should I take tape measurements?
Every two to four weeks is enough; body composition changes slowly. Always measure at the same time of day, before eating or exercising, with the same tape placement.
Where exactly is the navel measurement taken for men?
Horizontally around the torso at the level of the belly button, at the end of a normal exhale. Do not pull your stomach in — that can cut several points off the estimate.
Is the tape method accurate for very muscular people?
It can underestimate body fat for lean bodybuilders because a thick neck raises the estimate of leanness. For most people it tracks within 3 to 4 points of lab methods, which is plenty for monitoring trends.