Body Fat Percentage Calculator

Pick your body type, or measure with a tape or calipers.

By Nick · Updated

You

Sex
Units

Method

How do you want to estimate it?

Pick the one that looks most like you. Close is good enough.

Wrap the tape level and snug, without pressing into the skin. Take three readings and use the average.

Pinch each site, read the calipers in millimeters, and use the average of three readings. The sites change with sex.

Estimates only. Talk to a doctor or registered dietitian before acting on these numbers for medical reasons.

What is body fat percentage?

Body fat percentage is the share of your total weight made of fat tissue. At 80 kg and 15% body fat, you carry 12 kg of fat and 68 kg of everything else: muscle, bone, organs, and water. That everything-else number is your lean body mass.

It answers a question the scale can't. Two people at the same weight and height can look and perform nothing alike, because one carries twice the fat of the other. Body fat percentage sees that gap; weight and BMI don't.

Body fat percentage vs BMI

BMI is weight divided by height squared. It never measures fat. A trained lifter and a sedentary person of the same height and weight share one BMI while sitting 15 percentage points apart on body fat. BMI screens populations; body fat percentage measures an individual.

Body fat percentage vs scale weight

Scale weight moves with water, glycogen, and food in transit, often by 1 to 2 kg inside a single day. Body fat changes slowly, over weeks. During a cut the scale can stall while body fat keeps dropping, which is the whole reason to track composition rather than weight alone.

How does this calculator work?

The tape and caliper methods estimate body fat from measurements. The body type method uses the middle of the range for the picture you pick. Then this page turns the result into fat mass, lean mass, and a recommended deficit. The how Deficit works page covers the math and the research behind each step.

The U.S. Navy method (tape measure)

The Navy method estimates body fat from circumferences: neck and waist for men, plus hips for women. It needs a flexible tape measure and nothing else. The formulas come from two 1984 Navy studies, one of men and one of women. Men measure the waist at the navel. Women measure the waist at its narrowest point and the hips at their widest. The step-by-step guide shows where to put the tape and where to pinch for calipers. 

Men:   %BF = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76
Women: %BF = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387

All measurements in inches inside the formula; the calculator converts for you when you pick metric.

Jackson-Pollock 3-site (skinfold calipers)

Calipers measure the fat directly under the skin at three sites. The Jackson-Pollock equation converts the sum of those folds, plus your age, into body density, and the Siri equation converts density into body fat. Men pinch chest, abdomen, and thigh; women pinch triceps, suprailiac, and thigh. 

Men:   density = 1.10938 − 0.0008267×sum + 0.0000016×sum² − 0.0002574×age
Women: density = 1.0994921 − 0.0009929×sum + 0.0000023×sum² − 0.0001392×age
%BF    = 495 / density − 450   (Siri)

Body fat percentage chart for men and women

These are the six body types the calculator and the Deficit app use. Women carry more essential fat than men (about 10 to 13% against 3 to 5%), so each type sits at a higher number for women.

Body typeMenWomen
Shredded Drawing of a man at 6–10% body fat 6–10% Drawing of a woman at 12–18% body fat 12–18%
Lean Drawing of a man at 10–15% body fat 10–15% Drawing of a woman at 18–23% body fat 18–23%
Athletic Drawing of a man at 15–20% body fat 15–20% Drawing of a woman at 23–28% body fat 23–28%
Average Drawing of a man at 20–26% body fat 20–26% Drawing of a woman at 28–34% body fat 28–34%
Soft Drawing of a man at 26–32% body fat 26–32% Drawing of a woman at 34–40% body fat 34–40%
Heavy Drawing of a man at 32–40% body fat 32–40% Drawing of a woman at 40–48% body fat 40–48%

Shredded is the level physique competitors hold for a stage. Almost nobody stays there all year, because sitting that low for long costs hormones and recovery.

How accurate is each method?

No at-home method is exact. In the studies that built them, both formulas missed underwater weighing by a typical 3.5 to 4 points of body fat:

  • Navy tape: 3.5 points for men and 3.7 for women. In later check groups the error was 2.7 to 4.4 points.
  • Skinfold calipers (3 sites): 3.6 to 4 points in the women's study.
  • Body type pictures: a range, not a measurement. Use it to start a plan, then measure.

The tape also leans one way: it tends to read high in lean people and low in people with more fat. Bio-electrical impedance (the smart-scale method) sends a small current through the body and infers fat from resistance. Hydration throws it off by several points, so read the trend across weeks and ignore the absolute figure. Smart scales, InBody, DEXA and the BodPod are compared in how accurate is each way to measure body fat.

Does the Navy tape method track changes in body fat?

Not well over a few weeks. In a 2023 study of 1,407 Army recruits, DXA scans measured a loss of about 3 to 4 points of body fat over 8 weeks of training. The tape found about two thirds of that loss in men and none of it in women. For 43% of the women it showed a gain while the scan showed a loss. An earlier study of 150 women in basic training found the same problem.

So measure every week, the same way, and read the trend over several weeks. Do not read much into one week's change of a point or two.

Which method should you use?

Pick one and stay with it. Switching methods mid-cut introduces a calibration gap that looks like progress or its opposite when nothing changed.

  • No tape, want a rough number. Pick the body type picture that looks most like you.
  • No gear, want a measured number. Use the Navy method. It's free and takes two minutes. Measure weekly and read the trend, not one week's change.
  • Have calipers and a steady hand (or a partner). Skinfolds measure fat directly rather than inferring it from circumferences, so they read truer in trained people once your technique settles.
  • Want a real baseline. Book a DEXA at the start of a cycle and another at the end. Two accurate points bracket the whole cut and tell you how much fat you lost versus lean mass you kept.

What should you do with your body fat number?

On its own the number does little. In a cut it sets three things: how big a deficit you can run, how much protein you need, and your resting burn, which comes from your lean mass.

The calorie deficit calculator takes it from here: daily calories, protein and the date you reach your goal. For protein alone, use the protein calculator.

Body fat calculator questions

How accurate is the U.S. Navy body fat calculator?

In the original Navy studies, the formula missed underwater weighing by a typical 3.5 points of body fat for men and 3.7 for women. It tends to read high in lean people and low in people with more fat.

Can I estimate body fat without measurements?

Yes. Pick the body type picture that looks most like you, and the calculator uses the middle of its range. It is close enough to start a plan. Measure with a tape or calipers when you want a number to track.

Do I need my weight to use this calculator?

No. Body fat percentage comes from the measurements alone. Adding weight unlocks two extra numbers, fat mass and lean body mass, since both are a share of total weight.

Why do the skinfold sites change between men and women?

Men and women store fat differently, so the Jackson-Pollock equation uses sex-specific sites: chest, abdomen, and thigh for men; triceps, suprailiac, and thigh for women. The calculator swaps the labels when you change the sex setting.

Which is better, the Navy method or skinfolds?

Both have a typical error of about 3.5 to 4 points. Skinfolds need calipers and practice; the Navy method needs only a tape measure, but it misses small changes over a few weeks. The one you will repeat the same way every time wins.

How often should I remeasure?

Once a week, on the same day and under the same conditions: same tape or calipers, same time of day, before you eat or train. One week's change is mostly noise, so read the trend over several weeks.

Can smart-scale body fat be trusted?

Not the single reading. Bio-electrical impedance can miss by five points or more depending on hydration. The weekly trend is useful; the daily number isn't.

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