Precision Nutrition’s Body Fat Calculator

Want to know your body fat percentage? This free body fat calculator estimates it instantly, using three scientifically validated formulas.

But that’s just for starters: Our body fat calculator does way more than spit out numbers.

In addition to getting your body fat percentage estimate, you’ll also receive a FREE report that’ll help you understand what your results REALLY mean—and what you should do next to reach your health and fitness goals.

Ready to see your body fat percentage and get your report?

Enter your details below. (Have questions? Find the answers below the body fat calculator.)

Body Fat Calculator


If intersex or transitioning, choose the biological sex description that best fits current hormonal status for interpreting body fat ranges.


Originally used by the YMCA. It uses waist circumference, body weight, and sex.


Developed at Navarra University in Spain. CUN BAE is an acronym for Clinica Universidad de Navarra (CUN) Body Adiposity Estimator (BAE). It uses body weight, height, age, and sex.



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Your Results

Your estimated body fat percentage


Body weight:


Fat mass:


Lean mass:


Not sure what to do with these numbers?

We’ve created a FREE report that analyzes your body fat results and shows you what to do next.

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Understand what your body fat level means for your health

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Adjust your nutrition and lifestyle to achieve your body fat goals

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Learn new strategies for making healthy changes that last

Your personalized report is on the way!

How to use this body fat calculator

Whether you’re checking your own body fat percentage or doing the calculations for a client, here’s the information you’ll need:

  • age
  • sex
  • height
  • weight
  • waist circumference
  • hip circumference
  • neck circumference

You’ll know the first few details off the top of your head. But what about your neck, waist, and hip circumference? Just grab a measuring tape and use the instructions below.

This graphic is titled “How to Take Your Measurements” and provides details on how to use a measuring tape to get your neck, waist, and hip circumferences . Here are the instructions: 1) Neck: Measure at the widest part of your neck; 2) Waist: Measure at the narrowest part of your waist (usually around your navel); 3) Measure at the widest part of your hips. Tip: To get an accurate measurement, the measuring tape should be snug, with no gaps between the tape and your skin—but not so tight it’s cutting into your skin.

Who’s this body fat calculator for?

This body fat percentage calculator is for anyone who is curious about how much body fat they have and doesn’t have access to a more advanced method.

It’s also useful for health, fitness, and nutrition coaches who want to estimate their clients’ body fat percentages for goal setting, intake evaluations, and tracking progress. (Learn more about our #1 rated nutrition coaching certification program here.)

How does this body fat percentage calculator work?

Our body fat calculator takes the inputs listed above and enters them into three scientifically validated body fat percentage formulas (those used for the Navy body fat percentage calculator, the YMCA body fat percentage calculator, and the CUN BAE body fat percentage calculator).

Obviously, this online body fat percentage calculator can’t measure your body fat directly—so it doesn’t give you an exact body fat readout.

But research shows each of these body fat calculator methods are around 95 percent accurate when working with large populations.

That means it’s going to be pretty close for most people, but for some—especially those who 1) are very lean and muscular (think: bodybuilders, football players, gymnasts) or 2) have very high levels of body fat—it’s going to be less accurate.

What this body fat calculator can do (and what it can’t do)

This body fat calculator estimates the percentage of your body weight that is fat mass.

Fat mass is exactly what you think it is: All the fat on your body.

The body fat calculator also estimates your lean mass. Simply put, lean mass is anything that isn’t fat mass—muscle, bone, organs, connective tissue, water, and even stuff inside your GI tract.

These numbers will give you an idea about your potential health risks.

Even with an accurate measurement, though, your level of body fat doesn’t define your health status.

For instance, it’s possible to be very healthy at a higher body fat percentage. Or very unhealthy at a lower body fat percentage. (Get your free, personalized report to learn more about how your body fat percentage affects your health risk.)

Do you have a healthy body fat percentage?

Using the body fat percentage chart below, you can see where your body fat falls in terms of general categories.

A body fat percentage chart showing low, normal, high, and very high body fat categories for different age groups, for both women and men. Here are how the body fat percentages break down by category. Women, Ages 20-39: Low = <21%; Normal = 21.0-32.9%; High = 33.0-38.9; Very High = ≥ 39. Women, Ages 40-59: Low = <23; Normal = 23.0-33.9; High = 34.0-39.9; Very High = ≥ 40. Women, Ages 60-79; Low = <24; Normal = 24.0-35.9; High = 36.0-41.9; Very High = ≥ 42. Men, Ages 20-39: Low = <8%; Normal = 8.0-19.9%; High = 20.0-24.9; Very High = ≥ 25. Men, Ages 40-59: Low = <11; Normal = 11.0-21.9; High = 22.0-27.9; Very High = ≥ 28. Men, Ages 60-79; Low = <13; Normal = 13.0-24.9; High = 25.0-29.9; Very High = ≥ 30.

This data is based on available research. If you’re an adult who falls outside these age ranges, it’s reasonable to use the body fat percentage category closest to your age. Also, the “Normal” category for body fat level is the label used by the scientists and guidelines we’ve cited, but it’s not our view that folks whose body fat falls below or above this range are “abnormal” or inherently unhealthy.

But remember: Your results won’t be 100 percent precise. They’re our best guess, based on the limitations of the measurement methods used here.

Additionally, the exact numbers aren’t what matter most.

The main benefit of this body fat percentage calculator is to help you assess where you currently are, compared to where you want to be. (If you’re interested in losing body fat, check out our free weight loss calculator.)

Recognize that this body fat percentage estimate doesn’t define you. It’s just one piece of the large puzzle that is your health—and which is influenced by many factors, including how you consistently eat, move, sleep, and deal with stress.

If you’d like to better understand what your grouping means, you’ll find that info—and more—in your FREE body fat percentage report. (Just put your details into the body fat percentage calculator.)

Body fat percentage: The bottom line

Most people don’t need to know their exact body fat percentage in order to make decisions about what comes next for them.

Because of that, the estimate from this body fat calculator will do the job nicely. (Plus, it’s fast, free, and user-friendly.)

Understanding which general body fat percentage range you’re in can help you:

  • Make informed decisions about your health
  • Decide what your body composition goals are (if any)
  • Provide a starting point for tracking your body fat percentage over time

Beyond that, here’s our best advice:

Your body fat percentage is just one indicator of your physical health.

And your physical health is just one factor that determines your overall health.

In fact, it’s not publicized enough: Your emotional health, mental health, social connections, environment, and sense of purpose in life all play vital roles in your total well-being.

So remember: If your goal is to thrive, perform, and live as well as you can, your body fat percentage is just a snapshot—not the whole picture album.


How accurate are body fat percentage calculators?

Reasonably accurate, generally speaking. But an online body fat calculator isn’t the MOST accurate way to determine your body fat percentage.

There are many different methods you can use to calculate body fat percentage.

Here are the most common body fat measurement methods, in order from most accurate to least accurate.

1. DEXA scan

Dual Energy X-ray Absorptiometry (DEXA) involves using low-level X-ray beams to determine your fat-free mass, fat mass, and bone mineral density.

DEXA is the most accurate method of body fat measurement, but one downside is that it’s not readily available in every geographic area, and it can be relatively expensive compared to other methods.

2. Hydrostatic weighing

This method involves first being weighed, then being weighed again while submerged in water. Because fat is less dense than water, a person with more body fat will weigh less under water.

This is also a very accurate way to measure body fat percentage (it was the gold standard before DEXA), but it’s not commonly used outside of research settings. (It requires a deep hot tub-looking tank and, fun fact, an autopsy scale.)

3. Air-displacement plethysmography (Bod Pod)

A machine estimates body fat percentage in a way similar to hydrostatic weighing, only using air pressure instead of water.

This method is relatively accurate and more readily available (more and more gyms have them now), but is more expensive than the less accurate options below.

4. Skinfold measurements

A caliper is used to measure the thickness of the fat and skin in several areas of the body. Then, those numbers are plugged into a formula to determine body fat percentage.

The accuracy of this method depends on the skill level of the person taking the measurements. To track changes over time, it’s important that the same person does all the measurements.

Also, this method may not be accurate for those with very high levels of body fat.

5. Girth measurements

Body girth measurements (like the ones used in the body fat percentage calculator on this page) can be plugged into formulas with other information such as height, weight, age, and sex to estimate body fat percentage.

While it isn’t the most accurate approach, it is one of the easiest and doesn’t require special equipment (other than a measuring tape).

This method is especially useful to measure progress over time, as changes in girth can indicate changes in muscle mass and body fat.

6. Bioelectric impedance

Scales that measure body fat percentage use this method. Essentially, the scale sends an electric current through your body and measures the resistance.

Fat produces more resistance than muscle and water, which helps the scale estimate your body fat percentage.

The problem: This method can be sensitive to hydration status. (So your results could fluctuate even on the same day.)

7. Bodyweight alone

Changes in weight may reflect body fat loss or gain, but a scale won’t tell you whether weight gained or lost comes from muscle or fat.

What’s the deal with the three body fat formulas?

As mentioned earlier, this body fat calculator takes your inputs and enters them into three scientifically validated body fat percentage formulas:

  • The YMCA Body Fat Formula: Originally used by the YMCA. It uses waist circumference, body weight, and sex.
  • The Navy Body Fat Formula: Developed by the US Naval Health Research Center. It uses neck circumference and waist circumference for men, and neck circumference, waist circumference, and hip circumference for women.1
  • The CUN BAE Body Fat Formula: Developed at Navarra University in Spain. CUN BAE is an acronym for Clinica Universidad de Navarra (CUN) Body Adiposity Estimator (BAE). It uses body weight, height, age, and sex.2

We then average all three to give you a solid idea of where you stand. Each body fat percentage formula has its benefits and drawbacks, which is why we use all three to come up with a more realistic estimate.

“My body fat estimate doesn’t make sense!”

Okay, we’ve already noted that this body fat percentage calculator is just an estimate and that, depending on your specific body, may not accurately reflect your exact body fat percentage.

But let’s explore this a little more.

Say a million random people use the calculator. Odds are, 950,000 of them will find it provides a pretty believable estimate.

At the same time, it could be way off—or totally unbelievable—for 50,000 of those folks.

While 50,000 can seem like a lot of people, compared to 950,000, it’s pocket change.

Think of it this way: In the general population, there aren’t a lot of people— percentage-wise—built like an NFL linebacker.

You, however, might be.

Or you might fall on the other end of the body composition spectrum.

Formulas—like the ones in this body fat calculator—that have been developed to estimate body fat percentage from circumference measurements simply aren’t sensitive enough to account for all body types, particularly those that are furthest away from the average.

But… they’re the best formulas we’ve got based on scientific research.

Again, these numbers don’t define you. They’re just data you can use to measure changes over time.

Your age, sex, and ethnicity impact your results.

People vary widely in their body shapes and sizes. We’re all unique individuals.

In addition, several other factors influence your body fat percentage and body fat distribution, including:

➤ Age

As you age, you tend to lose lean mass and gain body fat. You also tend to accumulate more visceral fat.

➤ Sex

On average, males and females tend to have different levels of body fat. Plus, that fat is often distributed on their body differently, thanks largely to the effects of hormones.3,4,5,6

Males generally tend to gain fat more around the middle.

Females tend to gain fat more around their lower bellies, hips, and thighs as well as in breast tissue.

However, males whose bodies convert testosterone to estrogen more easily may also put on fat in breast tissue and around their hips and thighs, similar to a typically female pattern of fat distribution.

Males and females tend to differ in how much body fat is optimal for health, function, longevity, and performance.

In general, female bodies prefer higher ranges of body fat for overall health.

And, on average, males tend to have more lean mass across their lifespan than females.

What if I’m intersex or trans?

To date, there are no reliable calculations for people who are intersex or transgender. (This is due to a lack of scientific data in this area.)

Typically, the most accurate guess will come from using the body composition calculations that are closest to a person’s current hormonal profile.7,8

Supplemental hormones such as estrogen and testosterone will, over time, affect lean mass and body composition.

For example:

Trans men who have been supplementing testosterone for at least six months, and have had top surgery to eliminate breast tissue, may find the male body composition equation to be most accurate.

Trans women who have been supplementing estrogen for at least six months may find the female body composition equation to be most accurate.

➤ Ancestry/ethnicity

There may be meaningful differences between ethnic groups.9,10,11,12,13

This occurs both in terms of how accurately the body fat calculation’s estimate represents reality, and also for predicting health and disease risk.

For instance, people with some types of South and East Asian ancestry may have a higher risk of metabolic disease (such as cardiovascular or Type 2 diabetes) at a relatively lower level of body fat compared to someone of Western European descent.

And people from populations who typically have heavier and denser bodies—such as many indigenous South Pacific peoples—may be categorized as “obese” or in a higher-risk category, despite this body type not being associated with negative health effects for them.



Click here to view the information sources referenced in this article.

1. Peterson DD. History of the U.S. Navy Body Composition program. Mil Med. 2015 Jan;180(1):91–6.

2. Gómez-Ambrosi J, Silva C, Catalán V, Rodríguez A, Galofré JC, Escalada J, et al. Clinical usefulness of a new equation for estimating body fat. Diabetes Care. 2012 Feb;35(2):383–8.

3. Kirchengast S. Gender Differences in Body Composition from Childhood to Old Age: An Evolutionary Point of View. J Life Sci R Dublin Soc. 2010 Jul 1;2(1):1–10.

4. Nauli AM, Matin S. Why Do Men Accumulate Abdominal Visceral Fat? Front Physiol. 2019 Dec 5;10:1486.

5. Schorr M, Dichtel LE, Gerweck AV, Valera RD, Torriani M, Miller KK, et al. Sex differences in body composition and association with cardiometabolic risk. Biol Sex Differ. 2018 Jun 27;9(1):28.

6. Wells JCK. Sexual dimorphism of body composition. Best Pract Res Clin Endocrinol Metab. 2007 Sep;21(3):415–30.

7. Klaver M, de Blok CJM, Wiepjes CM, Nota NM, Dekker MJHJ, de Mutsert R, et al. Changes in regional body fat, lean body mass and body shape in trans persons using cross-sex hormonal therapy: results from a multicenter prospective study. Eur J Endocrinol. 2018 Feb;178(2):163–71.

8. Klaver M, Dekker MJHJ, de Mutsert R, Twisk JWR, den Heijer M. Cross-sex hormone therapy in transgender persons affects total body weight, body fat and lean body mass: a meta-analysis. Andrologia. 2017 Jun;49(5).

9. Deurenberg P, Deurenberg-Yap M. Differences in body-composition assumptions across ethnic groups: practical consequences. Curr Opin Clin Nutr Metab Care. 2001 Sep;4(5):377–83.

10. Ortiz O, Russell M, Daley TL, Baumgartner RN, Waki M, Lichtman S, et al. Differences in skeletal muscle and bone mineral mass between black and white females and their relevance to estimates of body composition. Am J Clin Nutr. 1992 Jan;55(1):8–13.

11. Wagner DR, Heyward VH. Measures of body composition in blacks and whites: a comparative review. Am J Clin Nutr. 2000 Jun;71(6):1392–402.

12. Jackson AS, Ellis KJ, McFarlin BK, Sailors MH, Bray MS. Cross-validation of generalised body composition equations with diverse young men and women: the Training Intervention and Genetics of Exercise Response (TIGER) Study. Br J Nutr. 2009 Mar;101(6):871–8.

13. Chumlea WC, Guo SS, Kuczmarski RJ, Flegal KM, Johnson CL, Heymsfield SB, et al. Body composition estimates from NHANES III bioelectrical impedance data. Int J Obes Relat Metab Disord. 2002 Dec;26(12):1596–609.

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