Body Fat Calculator for Women: Tape Measure (Navy Method)

Body Fat Calculator for Women

Estimate your body fat percentage with a tape measure, using the women's version of the U.S. Navy method.

Last updated September 24, 2026

Your details

Units

US (lb)UK (st)Metric (kg)

Sex

FemaleMale

Weight

Height

Neck

Just below the voice box, tape sloping slightly down to the front.

Waist (narrowest point)

Relaxed, at the end of a normal breath out.

Hips (widest point)

Estimated body fat (U.S. Navy method)

28.6%

Average. For women, the American Council on Exercise calls 25–31% average and 32% or more the obesity range.

What that means in weight
	Amount
Fat mass	41 lb
Lean mass (everything else)	104 lb

Tape methods are estimates. Measure 2–3 times and use the average.

Not medical advice. If you have kidney disease, diabetes, or take prescription medication, talk to your doctor or a registered dietitian before changing your protein intake. Read our full disclaimer.

Why women's ranges are higher

Women naturally carry more body fat than men. That is why the "average" range for women sits well above the range for men: 25% to 31% for women versus 18% to 24% for men, according to ACE.

So don't compare your number with a man's, or with a fitness model's photo. Compare it with the ranges for women, and with your own past results.

What this version sets up for you

This page starts with the female setting, which uses the women's Navy formula. It needs four numbers: height, neck, waist, and hips. The men's version skips the hips.

With the sample numbers (5 ft 5 in or 165 cm tall, a 13 in or 33 cm neck, a 30 in or 76 cm waist, and 38 in or 97 cm hips), the estimate is about 28.6%. That sits in the ACE average range. You'll also see how much of your weight is fat and how much is lean mass.

How to measure

Waist: at the narrowest point, relaxed, after a normal breath out.
Hips: at the widest point around your buttocks.
Neck: just below the voice box, with the tape sloping slightly down to the front.

Measure each spot 2 or 3 times and use the average. Skip this during pregnancy, since your waist and hips change for other reasons.

Your waist alone also tells you something. The WHO links a waist over 80 cm (31.5 in) in women with increased health risk. Our waist-to-hip ratio calculator looks at this in more detail.

See the full body fat percentage chart, or go back to the main body fat calculator.

Frequently asked questions

What is a healthy body fat percentage for a woman?

The American Council on Exercise (ACE) lists 25% to 31% as average for women who are not athletes, and 32% or more as the obesity range. ACE also warns that going below about 14% may be dangerously low for women.

Why does the women's body fat formula use hip size?

The U.S. Navy researchers measured women and men separately and built a formula for each. The women's formula uses waist, hips, and neck along with height. The men's version uses only the waist and neck.

Is 30% body fat bad for a woman?

Not by ACE standards. 30% falls inside the 25% to 31% range ACE lists as average for women. Other measures, like your waist size and your overall health, matter too.

How accurate is a tape measure body fat calculator?

It gives an estimate, not an exact number. Small changes in where you place the tape can shift the result. Measure the same way each time and track the trend over weeks rather than trusting one reading.