Body Mass Index and Body Fat Percentage: The Difference Explained

Published By: Debbie Luna
Last Updated:
October 18, 2021

Body Mass Index and Body Fat Percentage are two methods to measure your body’s level of fitness. Though lots of individuals tend to interchange them, both should be used for entirely different situations or phases in your journey to a healthier self. Getting a broader and more precise understanding of each will allow you to track your progress with accuracy and ease.

Understanding Body Mass Index or BMI

To get your Body Mass Index (BMI), you will need to measure weight and height and correlate it to a standard chart that’s created by experts. Physicians commonly use BMI as a fast way to determine if one is underweight, within the ideal weight range, overweight, or obese.

exercise woman health

To find out what your BMI is, you should convert your weight into pounds and multiply this by 703. Next, divide this with your height in inches squared (height in inches x height in inches). The given guidelines are as follows: 18.5 below (underweight), 18.5 to 24.9 (normal), 25.0 to 29.9 (overweight), 30.0 and above (obese). While this method is often used, it does have its disadvantage—it is not invented to measure how much your muscle and fat weight is.

If you are, for instance, an athletic individual, you will be more substantial in terms of muscle mass compared to an average individual. If this is the case, BMI might not be as accurate when you want to check your fitness and health. People who are physically active or are inclined to sports have higher BMI scales.

The Role of Measuring Body Fat Percentage

man weighing bmi

When other factors could influence an individual’s BMI significantly, Body Fat Percentage is introduced to the situation. By getting a person’s Body Fat Percentage, one will be able to determine what percentage of their body is composed of fat. By doing this, the person will see a more accurate and more precise picture of their level of fitness, especially for athletes.

To be able to ascertain your ideal Body Fat Percentage, use this formula: (120 x BMI) divided by (0.23 x Age). Use the reference below as your guideline for assessing your Body Fat Percentage.

  • Men: 2 – 4 percent (essential fat); 6 – 13 (athlete category); 14 – 17 (fit); 18 – 25 (acceptable), 25 percent above (obese)
  • Women: 10 – 12 percent (essential fat); 14 – 20 percent (athelete category); 21 – 24 (fit); 25 – 31 percent (acceptable); 32 percent above (obese)

Besides this, we recommend you have a look at this body fat calculator at for simpler and faster results.

The Combination of Both BMI and Body Fat Percentage

woman measuring bmr

Gathering your BMI and Body Fat Percentage and comparing both to your lifestyle habits can be a surefire way to measure your level of fitness and your progress. Some people also claim that the trick to getting visible abs is to maintain a Body Fat Percentage within the athlete category. By carefully comparing the two tools to each other and correlating them to your eating and lifestyle habits, you’ll be able to see a richer picture of your fitness state.

Closing Thoughts

If you are starting with your fitness journey, then it is suggested that you use your BMI to check your progress. As you level up your workout routine and lose more weight, you should gradually shift to measuring your Body Fat Percentage instead. In the long haul, measuring your Body Fat Percentage is believed to be the most accurate and preferred gauge for tracking fitness progress.

Debbie (Deb) started powerlifting and Olympic lifting in High School as part of her track team's programming; She continues to train in order to remain athletic. Inspire US allows Deb to share information related to training, lifting, biomechanics, and more.
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