Free Body Fat Calculator

Body Fat Calculator

Enter a few tape measurements to estimate your body fat percentage with the US Navy method. You get your category, fat and lean mass in kg, and a waist check calibrated for Indian bodies.

Sex
Measurement Unit

Your body fat estimate will appear here.
An estimate, not a diagnosis. Tape-based formulas are typically within about 3–4 percentage points of a DEXA scan. They are less reliable during pregnancy, for very muscular or very heavy people, and for under-18s. For a medical assessment, speak to your doctor.

How This Body Fat Calculator Works

Body fat percentage is the share of your body weight that is fat. Two people can weigh exactly 75 kg and look completely different: one at 14% body fat, the other at 28%. That is why body fat says far more about your physique and metabolic health than the scale or BMI alone. This calculator uses the US Navy circumference method, a formula built from tape measurements and validated against underwater weighing. You only need a soft measuring tape.

1. The US Navy formula

Fat tends to collect around the waist (and, for women, the hips), while neck size tracks frame and muscle. The formula compares these circumferences against your height. With all measurements in centimetres:

Men: %BF = 495 / (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450
Women: %BF = 495 / (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.22100 × log10(height)) − 450

If you switch to inches, the calculator converts everything to centimetres first, so the result is the same. Fat mass is your weight multiplied by your body fat percentage, and lean mass (muscle, bone, organs and water) is everything else.

As a cross-check, it also shows the Deurenberg BMI-based estimate: 1.20 × BMI + 0.23 × age − 10.8 × sex − 5.4 (sex is 1 for men, 0 for women). It needs no tape, but because it only knows your height and weight it cannot tell muscle from fat. Trust the Navy number more if you lift.

2. How to measure (this is where accuracy is won or lost)

3. Body fat categories (ACE)

The calculator labels your result using the American Council on Exercise ranges. Women naturally carry more essential fat, so their ranges sit higher.

CategoryMenWomen
Essential fat2–5%10–13%
Athletic6–13%14–20%
Fit14–17%21–24%
Average18–24%25–31%
High25% and above32% and above

"Essential" is the minimum your hormones and organs need. It is a stage-day number for bodybuilders, not a goal. For most people, getting into the fit range is where health markers, energy and appearance all improve noticeably.

4. Why Indians should watch the waist

Research on South Asians has repeatedly found that, at the same BMI, Indians carry more total body fat and more abdominal and visceral fat (the fat around the organs) than Europeans. This "thin-fat" pattern is one reason type 2 diabetes and heart disease show up earlier and at lower body weights in India. It is why Indian guidelines use a lower BMI cut-off for overweight (23 rather than 25), and why a waist of 90 cm or more for men or 80 cm or more for women is treated as a flag. The calculator checks your waist against these thresholds separately from your body fat result. If you look slim but your number is higher than expected, read our skinny-fat diet plan for India.

5. How accurate is it?

For most adults the Navy method lands within about ±3–4 percentage points of a DEXA scan. That is similar to most smart scales, and far cheaper. It tends to overestimate body fat in very lean, muscular men with thick necks and waists, and it can underestimate in people who carry fat mainly on the hips and thighs. The BMI-based estimate is less precise still, often off by 4–5 points for individuals. Two practical rules follow:

6. What to do with your number

If your result is average or high, the goal is a moderate calorie deficit with enough protein to keep muscle. Start with our TDEE and calorie calculator to set your daily calories, then use the protein calculator to set your protein target. Men carrying most of it around the middle should read how to reduce belly fat for Indian men. If you are already in the fit range and want visible abs, the shredded body guide covers the final phase. Whatever your starting point, re-measure every few weeks and judge progress by the trend.

Body Fat FAQs

How accurate is the US Navy body fat calculator?

For most adults the US Navy method lands within about 3–4 percentage points of a DEXA scan. That is good enough to place you in the right category and very useful for tracking change over time, but it is not a lab measurement. Errors are larger for very lean, very muscular or very heavy people, and when the tape is placed inconsistently.

What is a healthy body fat percentage?

Using the American Council on Exercise ranges, about 14–24% is fit to average for men and about 21–31% for women. Below roughly 6% for men or 14% for women is essential-fat territory and not a sustainable target. Above 25% for men or 32% for women is classed as high and is linked with higher metabolic risk.

Why do Indians have higher body fat at the same BMI?

Studies consistently find that South Asians carry more body fat, and more of it around the abdomen and organs, than Europeans of the same BMI. This is often called the thin-fat Indian phenotype. It is why lower BMI cut-offs (23 for overweight) and waist thresholds of 90 cm for men and 80 cm for women are used for Indians.

How do I measure my waist and neck for body fat?

Use a soft tape, stand relaxed and do not suck in. Men measure the waist horizontally at the navel; women measure at the narrowest point between the ribs and hips. Measure the neck just below the larynx (Adam's apple), with the tape sloping slightly down at the front. Women also measure the hips at the widest point of the buttocks. Take each measurement twice and use the average.

Is body fat percentage better than BMI?

For fitness goals, yes. BMI only uses height and weight, so it cannot tell muscle from fat: a muscular lifter can look overweight and a skinny-fat person can look normal. Body fat percentage and waist size say more about health risk and progress. BMI is still a quick screening number, so it helps to look at both.

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