Body composition · 6 min read
How to Measure Body Fat With a Tape Measure (US Navy Method)
You do not need calipers, a smart scale or a clinic to get a usable body fat estimate. A single cloth tape measure and the US Navy method, the same one this site uses, give you a number in about two minutes. Here is exactly where to measure, the formula behind it, and how far to trust the result.
What you need
Just two things: a flexible cloth or fibreglass tape measure (not a stiff metal one), and a quiet two minutes. Measure first thing in the morning, before eating or drinking, standing relaxed, with the tape snug against the skin but not compressing it. Always measure on bare skin, not over clothing.
Where to measure
The US Navy method uses body circumferences at specific sites. The measurements differ slightly by sex:
- Everyone: your height, and your neck, measured just below the larynx with the tape sloping slightly downward to the front.
- Men: the waist, measured horizontally at navel level.
- Women: the waist at its narrowest point, plus the hips at their widest point.
The formula
The method feeds those circumferences into a regression equation developed for the US Navy. In imperial units (inches):
You do not have to run this by hand. Our body fat calculator takes your measurements in centimetres or inches and applies the formula (and the metric version) for you.
A worked example
A man with a 34 in waist, 15.5 in neck and 71 in height (about 180 cm):
%BF = 86.010 x log10(34 - 15.5) - 70.041 x log10(71) + 36.76
= (86.010 x 1.267) - (70.041 x 1.851) + 36.76 = about 16 percent body fat.
How accurate is it?
The tape method is an estimate, not a gold standard. Against a DEXA scan it is usually within a few percentage points for typical body types, though it is less reliable for the very lean or for people who carry weight in unusual places. Its real strength is consistency: measure the same way each time and it tracks your change well, even if the absolute number is slightly off. For how it compares with calipers and DEXA, see body fat measurement methods compared.
Tips for a reliable number
- Measure at the same time of day, ideally fasted in the morning.
- Keep the tape level and snug, never digging into the skin.
- Take each measurement twice and average the two.
- Watch the trend over several weeks, not a single reading.
Enter your height, neck and waist (plus hips for women) and the calculator returns your body fat percentage and lean mass using the US Navy method.
Estimate your body fat now →Frequently asked questions
Can you measure body fat with just a tape measure?
Yes. The US Navy circumference method estimates body fat from your height, neck and waist (plus hips for women) using a validated formula. It needs no calipers or special equipment and takes about two minutes.
How accurate is the tape measure method?
It is usually within a few percentage points of a DEXA scan for typical body types. It is less precise than lab methods but very consistent, which makes it well suited to tracking changes over time, as long as you measure the same way each time.
Where do I measure for body fat?
Everyone measures height and neck. Men add the waist at navel level. Women add the waist at its narrowest point and the hips at the widest. Measure relaxed, on bare skin, with a snug, level tape.
Is the Navy method better than waist-to-height?
Waist-to-height is a quick health screen, while the US Navy method gives an actual body fat percentage and a lean mass figure. For tracking body composition the Navy method is more useful, and both improve when you measure consistently.
References
- Hodgdon JA, Beckett MB. Prediction of percent body fat for U.S. Navy men and women from body circumferences and height. Naval Health Research Center, Report No. 84-11; 1984.
- Lee SY, Gallagher D. Assessment methods in human body composition. Curr Opin Clin Nutr Metab Care. 2008;11(5):566-572. doi:10.1097/MCO.0b013e32830b5f23