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Body Fat Calculator: Find Your Real Body Fat Percentage (Male & Female)

Snap a photo and let the AI measure you, or grab a soft tape. Either way you get a reliable estimate from the proven U.S. Navy method, the same one the military has used for decades.

New: AI photo mode. Your photo never leaves your browser.

Your scale tells you one number. It cannot tell you what that number is made of. This body fat percentage calculator estimates how much of your weight is fat versus lean mass (muscle, bone, organs and water) using simple circumference measurements. That makes it far more useful than the scale or BMI, whether you are losing fat, building muscle or simply staying healthy.

AI photo

Or tape measure

Navy

Method

On-device

Nothing uploaded

Free

No sign-up

Instant

Results

What is your body fat percentage?

A few quick taps. Use a photo or a tape measure. No account, no email, nothing leaves your browser.

Body fat check1 of 6

How would you like to measure?

Both use the same validated Navy formula at the end.

Private, nothing saved

How AI photo mode works

Taking tape measurements is fiddly, and most people do it wrong. AI photo mode skips the tape. It runs a Google MediaPipe pose model directly in your browser, so your photo is never uploaded anywhere.

1

Find your body

The model detects 33 body landmarks and a full silhouette of you.

2

Scale to real size

Your silhouette height is matched to the real height you typed, giving centimetres per pixel.

3

Measure the rows

It measures your true width at the neck, waist and hips, ignoring arms held away from your body.

4

Apply the Navy formula

Widths plus depth become circumferences, which feed the same validated formula as tape mode.

Add a side photo for a better estimate

A front photo alone cannot see how deep your torso is front to back, so it assumes an average. A side photo measures that depth instead, which is why confidence jumps from medium to high.

What it is not

This is an educational estimate, not a medical device and not a DEXA scan. Lighting, baggy clothing and pose all move the number. If you want precision, use the tape, and re-measure the same way each time.

Now make the fat come off, and the muscle stay

One reading is a snapshot. What decides whether the fat stays off is your lean mass, and that is exactly what the scale hides. This matters most on a GLP-1, where up to 40 percent of the weight lost can be muscle if you do not protect it.

If you want to lose body fat

Check your pace with the weight loss percentage calculator, then set a protein target with the lean body mass and muscle retention calculator.

If you take a GLP-1

Find out where you stand with the GLP-1 Body Composition Tracker: are you losing fat or muscle?

Why Body Fat Percentage Beats BMI

BMI looks only at total weight and height. It cannot tell the difference between a muscular athlete and someone carrying extra fat. You can be a "normal" weight on BMI yet carry high visceral fat, the dangerous kind that surrounds your organs. Equally, you can be "overweight" on BMI yet lean and strong.

Body fat percentage tells the real story for:

Heart and metabolic health

Insulin sensitivity and diabetes risk

Hormone balance

Fat loss that does not cost you muscle

Athletic performance, and how you look and feel

That is why fitness professionals, doctors and serious trainees track body fat percentage instead of relying on the scale alone.

How to Calculate Body Fat Percentage at Home (U.S. Navy Method)

The Navy method is one of the most practical, reliable options for home use. It is not lab-perfect, but with consistent measurements it is accurate to within about 3 to 4 percent, more than enough for tracking change over time.

What you will need:

  • A soft fabric measuring tape (not metal)
  • A mirror, or someone to help
  • Relaxed posture and normal breathing

Best time to measure:

First thing in the morning, after using the bathroom and before eating or drinking. Repeat under the same conditions each time for the most useful trends.

Measurement Guide

Height

Stand straight against a wall, barefoot. Measure to the nearest 0.5 cm or 1/4 inch.

Neck

Just below the Adam's apple. Keep the tape level, sloping slightly down at the front. Do not tense or flare your neck.

Waist

Men, at navel level, relaxed. Women, at the narrowest point, usually just above the navel.

Hips (women only)

Around the widest part of the hips and buttocks.

Formulas (the calculator applies these automatically; measurements in inches):

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

Pro tip: measure each spot three times and take the average. Do not suck in your stomach or pull the tape tight.

Body Fat Percentage Ranges (Men & Women)

Healthy ranges vary by age, sex and goals. Here is the widely used American Council on Exercise (ACE) guidance:

CategoryMenWomen
Essential fat2 to 5%10 to 13%
Athletes6 to 13%14 to 20%
Fitness14 to 17%21 to 24%
Average18 to 24%25 to 31%
Obese25%+32%+

Women naturally carry more fat than men because of reproductive and hormonal needs.

Realistic targets (not extremes):

GoalMenWomen
General health10 to 20%18 to 28%
Visible definition12 to 15%20 to 24%
Competition lean (hard to maintain)6 to 10%14 to 18%

Staying too lean for too long can disrupt hormones, energy, immunity and bone health, especially for women. Speak to a doctor if you are concerned.

How the Navy Method Compares with Other Options

MethodAccuracyEase at HomeCostBest For
DEXA scanHighest (gold standard)Low$$$One-off detailed check
Hydrostatic / Bod PodVery highLow$$Research and clinical use
Navy tape (this tool)Good (about 3 to 4%)ExcellentFreeTracking progress
Skinfold calipersGood (with practice)High$More precise home option
Smart scales (BIA)VariableHigh$ to $$Rough daily estimates
BMIPoor for fatHighFreePopulation screening

For most people, the Navy method or calipers hit the sweet spot: accurate enough, free or cheap, and easy to repeat. Track every 2 to 4 weeks.

Using calipers? Pinch at standard sites (abdomen, thigh, triceps), and use the same calipers and technique every time. Jackson-Pollock formulas cover 3-site, 4-site and 7-site measurements.

Common Mistakes That Skew Your Results

  • Measuring after eating, bloating changes waist size
  • Sucking in your stomach or holding your breath
  • Measuring at different spots or times of day
  • Mixing units (cm vs inches)
  • Expecting one number to tell your whole story

Do this instead: log your measurements and percentage in a simple spreadsheet or app, then watch the trend. Combine it with photos, how your clothes fit, strength gains and energy levels.

Fat Loss vs Weight Loss: The Real Goal

You can lose weight and look softer, that is fat and muscle going. You can gain weight and look leaner, that is muscle coming on. What matters is body composition, not the scale.

Prioritise:

  • Strength training to preserve and build muscle
  • A protein-rich diet
  • A sustainable calorie deficit, not a crash diet
  • Sleep and stress management

If the scale stalls while your body fat percentage drops, you are winning.

Body Fat Percentage During GLP-1 Treatment

On a GLP-1, your body fat percentage tells you something the scale cannot: how much of your weight loss is actually fat, and how much might be muscle you would rather keep.

Here is the thing people miss. The scale gives you one number, your total weight, and it does not care whether a pound came off as fat, water, or muscle. Two people can both lose fifteen pounds and end up in completely different places, one leaner and stronger, the other just smaller and softer. Body fat percentage is what separates those two stories, and on a GLP-1, where the weight can come off quickly, it is worth watching.

It matters most on these medications because fast weight loss, plus a big drop in how much you are eating, can pull some of that weight from muscle instead of fat if you are not careful. Losing muscle is not just a physique thing. It is what quietly lowers your resting metabolism and makes the weight easier to regain later. The two habits that protect it are the ones you have probably heard before, because they genuinely work: enough protein every day (the macro calculator gives you a target) and some resistance training. That combination tells your body to hold onto muscle while the fat comes off.

This also explains the classic “the scale is stuck but I look different” moment. If you are losing fat while holding or building a little muscle at the same time, which is called body recomposition, your weight can barely move while your body fat percentage keeps dropping. That is a win, not a stall, and it is exactly why checking body fat and your measurements alongside the scale gives you the honest picture.

So while you are on a GLP-1, do not let the scale be your only scoreboard. Re-check your body fat every few weeks under the same conditions, keep your protein up, and keep lifting something. If your body fat is trending down, you are doing this right, even on the weeks the scale sulks. Your clinician is the right person to guide your overall plan, so keep them in the loop.

Losing weight, but not sure it is fat?

See how much of your loss is fat versus muscle, and watch the split over time instead of guessing.

Track Body Composition

Why Use This Calculator?

Uses the validated U.S. Navy formulas, with separate calculations for men and women
Gives clear, actionable results with context, not just a number
No data tracking, no ads, no products pushed at you

Health note: this is an educational estimate. See a doctor or registered dietitian for personalised advice, especially if you have a health condition or an extreme reading.

Track results, not just the scale

Watch your body fat fall without losing muscle

A single reading tells you where you are. What protects your results is logging body fat, weight and protein consistently, so you can see a direction instead of one dot. Calqulate Vitals keeps all of that on one timeline for free, and Premium adds the fat vs muscle trend, plateau risk and dose-timing views.

  • Log body fat, weight and measurements in seconds
  • Everything you log on one timeline
  • Find out how much protein is really in your meal
  • Fat vs muscle trend and plateau risk (Premium)
Start tracking freeSee how it works

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Frequently Asked Questions

Common questions and answers about our calculator

Tool Information

Last reviewed

June 2026

Reviewed by

Dr. Jaydeep Sanghani

Created by

Meet Akabari

Dr. Jaydeep Sanghani

Dr. Jaydeep Sanghani

MBBS, MD, DNB(Anaesth.), PDCC(CCM), DrNB(CCM)

AIIMS Bhubaneswar · AIIMS Rishikesh

Critical care specialist and anesthesiologist with advanced training from AIIMS. Reviews health calculators at Calqulate to ensure medical accuracy and evidence-based standards.

About the authors

Meet Akabari

Meet Akabari

·Co-Founder, Calqulate.net
Product StrategyProduct AlgorithmUser Acquisition
Krushal Barasiya

Krushal Barasiya

·Co-Founder, Calqulate.net
Software EngineeringCalculator DevelopmentTechnical SEO