Estimate your body fat percentage, body composition (lean to fat mass ratio), and fat category using the YMCA body fat formula.
Example: man, 30, 160 lb
15.9% body fat
About 15.9% body fat by the YMCA tape method, in ACE's Fitness range.
We found no published typical error for the YMCA tape method. Enter your own measurements above to replace this example.
Fat mass
25.4 lb
15.9% of your weight
Lean mass
134.6 lb
Everything else: muscle, bone, organs and water
Typical error
Not published
We found no published figure for this formula
American Council on Exercise body fat norms for men. The bands are the same at every age.
| ACE category | Men |
|---|---|
| Below essential fat | under 2% |
| Essential fat | 2 to 5.9% |
| Athletes | 6 to 13.9% |
| FitnessYou: 15.9% | 14 to 17.9% |
| Acceptable | 18 to 24.9% |
| Obesity | 25% and over |
| Method | Typical error | Body fat |
|---|---|---|
| YMCA tape methodThe method you chose | not published | 15.9% |
| BMI method (Deurenberg 1991) | ±4.1 | 18.2% |
The YMCA formula works out body fat from your waist and your weight. The categories are the American Council on Exercise's.
Sources: the YMCA formula, traced to Wilmore and Behnke 1969; American Council on Exercise (categories)
Next steps
There are many body fat calculators however, the body fat YMCA tool is one of the simpler calculators. It gives an approximation of body fat, body composition, and fat category based on gender, weight, and waist size.
What Does YMCA Stand For?
The acronym YMCA refers to the “Young Men’s Christian Association,” now commonly called “the Y”. The well-known organization was founded on June 6, 1844, by Sir George Williams and 11 others in London, England.
YMCA has grown immensely since being introduced to offer “healthy” activities to young men in major cities around the time of the Industrial revolution when the options were less than desirable.
While it has a deep history, we all know that today, the program focuses on youth development and prioritizes physical activities.
Fun fact: YMCA inspired the famous 1978 hit Y.M.C.A. by Village People.
What is The YMCA Calculator?
The calculator uses the YMCA formula to estimate body fat from your sex, weight, and waist size. YMCA is only the formula’s popular name: the studies that reproduce it trace it to research by Wilmore and Behnke on young men (1969) and young women (1970).
It does not require you to have a caliper or to take any skinfold measurements like several of the other calculators that we offer. Therefore, it’s a simple tool that anyone can use.
The YMCA body fat calculator uses equations for both males and females to estimate body fat, body composition, and fat category.
Male formula
Female formula
Try our US Navy body fat calculator to determine if you meet military standards.
Why Measure Body Fat?
Body fat plays a role in health, fitness, and performance. It can also be a predictor of health risks. Carrying too much body fat can increase the risk of Type 2 diabetes, cancers, heart disease, etc.
Having a waist measurement of 35 inches for women and 40 inches for men increases the risk of heart disease and diabetes according to the National Heart, Lung, and Blood Institute (1).
On the other side, having too little body fat can put you at risk for nutritional deficiencies and other undesirable side effects.
Performance and aesthetics
Health isn’t the only reason to monitor body fat. A healthy body fat percentage or percentage range makes you look and perform better.
There are some exceptions, of course, but in general, extra fat weighs you down and requires more energy to do activities.
If you want to be lean, you’ll need to have lower body fat. This varies between men and women as the former can be at a lower body fat level while women need more body fat to maintain good health and to support reproduction (2).
Related: 9 Common Reasons Why You Can’t Seem To Lose Body Fat
How accurate is the YMCA body fat tool?
There’s no way to know this exactly. We found no published typical error for the YMCA formula, so the calculator does not give one.
The best way to determine this is to use different body fat testing methods such as skinfold measurements and compare them to your YMCA body fat results.
Skinfold assessment with a caliper is one of the best options for most people because it’s relatively inexpensive compared to DEXA scans, hydrostatic weighing, and other more advanced options. The skinfold equations were built on caliper readings, so a pinch measured with a tape will not fit them.
Learn how to take skinfold measurements and enter them into our body fat skinfold calculator to estimate your body fat, body composition, and fat category.
How To Use The YMCA Body Fat Calculator
It doesn’t get much simpler than using the YMCA body fat calculator tool.
Step 1: Leave the Method menu on YMCA (tape measure, waist only). The menu also offers the US Navy, skinfold, and BMI methods.
Step 2: Choose your units: US (pounds and inches) or metric (kilograms and centimeters).
Step 3: Select your sex
Step 4: Type in your weight, height, and age
Step 5: Enter your waist size (measured at the navel/belly button)
Step 6: Press Calculate body fat
The YMCA formula itself uses only your sex, weight, and waist. The calculator asks for height and age to check that you are an adult and to show the BMI method’s estimate beside your YMCA result.
Now it’s time to analyze your numbers.
The calculator will show five pieces of information based on the details you entered into the tool.
- Body fat
- Fat mass
- Lean mass
- Typical error
- ACE category
Body fat is your body fat percentage or the percent of your body weight that is fat mass.
Fat mass is your body fat percentage in pounds/kg.
Lean mass is your lean mass percentage in pounds/kg. Lean mass includes body weight that is not fat such as muscle, bone, organs, and skin.
Typical error is how far a lab test would usually land from the method’s estimate. We found no published figure for the YMCA formula, so this tile reads “Not published”.
ACE category is the American Council on Exercise band your body fat percentage falls in: Essential fat, Athletes, Fitness, Acceptable, or Obesity. A figure under the essential fat line reads Below essential fat.
Under the category chart, a table puts your YMCA result beside the BMI method’s estimate from the same weight, height, and age.
So, for example, if you’re a 30-year-old male, 5 ft 10 in and 160 lb, with a 33-inch waist (the example the calculator opens with), you’d get the following results.
Body fat: 15.9%
Fat mass: 25.4 lb
Lean mass: 134.6 lb
Typical error: Not published
ACE category: Fitness
The comparison table puts the BMI method at 18.2% for the same man.
How To Measure Waist Size at The Navel
Aside from needing a scale to weigh yourself, you’ll also need a soft measuring tape to take your waist measurement. It’s important to do this part correctly to ensure you get the most accurate numbers.
The optimal time to take a measurement is soon after waking, ideally after using the bathroom and before eating or drinking anything.
Waist measurement
Stand up straight with your feet together and ideally in front of a mirror. Wrap the tape around the navel, also known as the belly button.
Make sure there are no spaces between the tape and your midsection but avoid overstretching the tape.
Take a normal breath and measure after you’ve exhaled. We recommend you take the measurement twice for best accuracy.
Body Fat Categories Table
The ACE category the calculator shows comes from this table, the American Council on Exercise body fat norms. ACE prints whole-number ranges, so each row here runs up to the start of the next one, the same way the calculator reads them. The chart has no age rows, so the same bands apply at every age.
| Category | Women (% fat) | Men (% fat) |
| Below essential fat | Under 10% | Under 2% |
| Essential fat | 10 to 13.9% | 2 to 5.9% |
| Athletes | 14 to 20.9% | 6 to 13.9% |
| Fitness | 21 to 24.9% | 14 to 17.9% |
| Acceptable | 25 to 31.9% | 18 to 24.9% |
| Obesity | 32% and over | 25% and over |
Difference Between Measuring Body Fat in Men vs. Women
The YMCA body fat calculator uses equations for both males and females to estimate body fat, body composition, and fat category.
Male formula
Female formula
Men and women have different body fat requirements. Women naturally have more body fat than men because of their reproductive nature.
The American Council on Exercise (ACE) offers a few body fat charts on their site that show recommended body fat percentages for both men and women.
“It’s comforting to know that women can be and should be fatter than men. They have a totally different reproduction function and the higher fat in women supports that reproductive function,” says Barbara J. Moore, PhD, president of Shape Up! America.
YMCA vs. BMI
While the YMCA calculator estimates body fat percentage and body composition, body mass index or BMI on its own does not. BMI determines whether someone is at a healthy body weight relative to their height.
It’s not always a good determiner of health though.
“If we think of BMI being a rough measure of body fatness, there are people, especially some highly trained athletes, who are overweight but not overfat,” explained Steven Heymsfield, MD, director of the Obesity Research Center at St. Luke’s Roosevelt Hospital in New York. “Likewise, there are people who are of a normal weight according to BMI scales but who are overfat. BMI is a broad, general measure of risk. Body-fat assessment is much more specific to your actual fat content and thus provides a more accurate picture.”
BMI is a useful tool, however, especially for the untrained, general population who get regular health checkups.
The YMCA tool offers something similar to BMI with an ACE category that shows where your body fat percentage sits on the American Council on Exercise chart. It also shows the BMI method’s body fat estimate (Deurenberg 1991), which turns BMI, age, and sex into a body fat figure. That method cannot tell muscle from fat, so treat it as a rough guide.
Also read: Most Effective Ways To Burn Body Fat Without Doing Cardio
Related Calculators:
- Body Fat Skinfold Calculator
- 3 Skinfold Body Fat Calculator
- 4 Skinfold Body Fat Calculator
- 7 Skinfold Body Fat Calculator
- Body Fat US Navy Calculator
- Calories Burned Weight Lifting
- Body Type Quiz
- Body Surface Area Calculator
- Calorie Deficit Calculator
Estimate Your Body Fat With The YMCA Body Fat Calculator
The YMCA body fat calculator is a simple-to-use tool that can give you a quick estimate of your body fat percentage, body composition, and fat category.
It may not be the most accurate tool but simplicity and convenience are where it’s advantageous over other body fat testing methods.
We do recommend you compare your results to other methods though and this way you can determine whether it’s close enough to give you something to work with.
