Body Fat Calculator: Get an Instant Body Fat Percentage

Calculate Your Body Fat Percentage With Simple Measurements

Body Fat Calipers
© Comstock / Stockbyte / Getty

There are different ways to measure your body fat percentage. Using a simple body fat calculator is the easiest method because it requires no special tools or lengthy appointments with a specialist. You'll need a basic tape measure and about five minutes to gather all the data you need to get an instant body fat measurement.

⁣How to Use the Body Fat Calculator

Follow these guidelines for calculating the most accurate body fat percentage.

When to Take Measurements

To get the most accurate result, you'll want to take measurements first thing in the morning. Your weight can fluctuate throughout the day so it's smart to get your numbers before you've had anything to eat or drink.

What to Use

Once you've weighed yourself, you'll need to take body measurements. Use a soft, flexible (cloth or fiberglass) tape measure to gather the numbers. Do not use a tape measure that is elastic.

How to Take Your Measurements

When you measure the circumference of each body part, the tape should feel firm enough against your skin so that it stays in place but not so tight that it causes an indentation.

You can use English or metric units. Measurements for men and women are slightly different.

Men

  • Current weight. Use a digital scale if possible.
  • Waist circumference. Take the measurement at the largest part of your belly, usually right at the level of your umbilicus (belly button). Make sure that the tape measure stays level to the floor. Don't hold your breath or suck in to get the measurement.

    Women

    • Current weight. Use a digital scale if possible.
    • Waist circumference. Take the measurement at the largest part of your belly, usually right at the level of your umbilicus (belly button). Make sure that the tape measure stays level to the floor. Don't hold your breath or suck in to get the measurement.
    • Wrist circumference. Measure around the smallest part of your wrist. You may need a partner to help with this measurement as it is hard to measure one-handed.
    • Hip circumference. Measure around the largest part of your hips, usually at the posterior extension of the gluteals (the place where your butt extends back).
    • Forearm circumference. Measure around at the widest part of your arm below your elbow. It will be easiest to have a partner get this measurement. Keep your arm relaxed during the measurement and let it hang alongside your body (don't bend or flex the arm while measuring).

    Once you've gathered your numbers, input the data to calculate your body fat percentage.

    Body Fat Percentage Categories

    Now that you've got your number, you probably want to know how your body fat percent compares to other men or women in various categories. According to the American Council on Exercise (ACE), there are five different ranges or body fat categories.

    Body Fat Percentage
    CategoryMenWomen
    Essential Fat  2-5 %  10-13%
    Athlete  6-13%  14-20%
    Fitness  14-17%  21-24%
    Acceptable  18-24%  25-31%
    Obese  over 25%  over 32%

    Keep in mind that these categories are based on body fat norms and may not be an indicator of your specific level of fitness or health.

    According to ACE, "a person's overall health and lifestyle choices should be taken into account before making a decision about whether their percent body fat is acceptable or unacceptable."

    Links to Disease Risks

    ACE notes that there is a large body of evidence that confirms an increased risk of chronic illness and disease for men with a body fat percentage higher than 25 and for women with a body fat percentage over 32.

    There are other measurements that might help you evaluate your risk for conditions like cardiovascular disease. If your body fat is too high according to the calculator, speak to your healthcare provider about different tools that you can use to measure your health risks.

    One of the most popular assessment tools is body mass index (BMI). BMI is a number that is used to evaluate your body size. It is not a percentage of body fat, but rather a general score that helps determine if your weight falls into a healthy range. The number is calculated using your weight and height. If you are carrying too much weight for your height, the excess weight is assumed to be fat. Body mass index is simply a tool that puts you into a category based on weight, it is not designed to be an accurate diagnostic tool for determining health.

    Why Measure Body Fat Percentage?

    Whether you liked your result or not, you may wonder why body fat percentage matters. In fact, if your goal is weight loss, you might be tempted to use a simple body weight scale for feedback on your progress. But body fat percentage tells you much more than the scale does.

    When you're trying to slim down, boost your health, or increase your level of fitness, fat loss should be your goal, rather than simple weight loss. You want to keep the lean mass, or fat-free mass, that your body needs. This includes bone, blood, connective tissue, organs, and muscle.

    Muscle loss sometimes occurs when you are losing weight, but it's not the kind of weight loss you are seeking. You want to maintain muscle mass because it helps your body to function and perform more efficiently, boosts your metabolism, and gives your frame a lean, tight appearance.

    By measuring changes in body fat percentage, you can tell how well your fitness or weight loss program is helping you to lose fat while maintaining fat-free mass.

    More Ways to Measure Body Fat Percentage

    There are many different ways to measure body composition (or the amount of fat and lean mass on your body). Using a body fat calculator is just one of them.

    Not every method is appropriate for everybody. For example, a person who is not comfortable being immersed in water should not try hydrostatic weighing. Each method also has pros and cons.

    Body Fat Calculator

    When you input body measurements into a body fat calculator like the one above, the tool uses a specific formula to estimate your percentage of fat. The formula is slightly different for men and women. 

    For women, the formula begins with a simple weight calculation:

    • (Total body weight x 0.732) + 8.987

    From there, the tool uses fractions of each body measurements to estimate your body fat percentage.  

    For men, the formula begins with a different weight calculation:

    • (Total body weight x 1.082) + 94.42

    From there, the tool uses a fraction of the weight measurement to estimate your body fat percentage.

    The body fat calculator is not the most accurate way of measuring body fat percentage, but because it is the easiest system to use, you might be able to use it more often. If you measure at the same time each day and use the same tools (the same tape measure and the same online calculator) you're likely to see important trends in your progress.

    Skin Caliper Measurements

    Some body fat calculators use skinfold measurements instead of body circumference measurements to estimate your body fat percentage. You can purchase skinfold calipers to use at home or you can hire a skilled professional to use them in a healthcare or gym setting.

    Skin calipers pinch a portion of your body to estimate fat levels. This method can be more accurate than the calculator with body measurements, but the accuracy depends completely on the skill level of the person using the calipers.

    Bioelectrical Impedance (BIA)

    Home scales, gym-quality scales, and devices in your healthcare provider's office may use bioelectrical impedance to estimate body fat. Simply put, the device sends a harmless, completely pain-free electrical signal through your body to measure fat. You get a quick and instantaneous body fat percentage result. While this method is convenient, certain factors such as hydration level can influence the accuracy of the result.

    DeXA Scanning

    This whole-body scanner is quickly becoming the gold standard for body fat measurement. However, one of the primary reasons that it is accurate is that the test is generally performed in a medical setting with highly skilled technicians. The test is often very expensive and may not be available in all areas.

    Hydrostatic Weighing

    This submersion method has long been recognized as the most accurate method of measuring body fat percentage. However, it requires that the subject fully immerse themselves into a tank of water and hold their breath. For many, this is a challenge. It can also be difficult to find locations to perform the test.

    There are other methods of measuring body fat, but the most common are listed above. If you plan to measure your body fat regularly, you should use the same method each time to get the most accurate data.

    How to Reduce Body Fat

    Now that you know your body fat percentage, are you inspired to reduce your numbers? The method is a simple equation: burn more calories than you eat. But, that doesn't mean that the process is easy. Reducing body fat means making changes in all areas of your life, not just in the way you eat and exercise.

    Reducing body fat should not be the goal for everyone. If you fall into the essential fat or even the athlete category, you may consider gaining weight and should speak with your healthcare professional before making a decision. Also, know that these numbers don't apply to pregnant women—you should not try to lose weight during pregnancy. You may also want to speak to your healthcare provider if you are trying to lose weight while on medications or during cancer treatment to make sure that it is safe to do so.

    These are areas you may want to focus on if reducing fat is appropriate for you:

    Your Diet

    How much you eat is a huge factor in losing or gaining body fat. You can always follow a popular diet, but fad diets generally don't work. What does work is to make small changes like:

    • Reduce your portion sizes.
    • Eat smaller meals more frequently throughout the day and avoid skipping breakfast.
    • Eat lots of fruits and vegetables to fill you up and give you the nutrients you need.
    • Eat more fiber. Fiber fills you up so that you don't have room for less healthy foods.
    • Avoid sugary drinks and junk food.
    • Limit how much alcohol you drink.

    Your Cardiovascular Fitness Program

    Cardiovascular exercise is an important part of any fat loss program, but you want to make sure you do the right kind of cardio. Make sure you're including some high-intensity interval training in your program, up to two to three times per week. You should also incorporate moderate and easy workouts as well.

    Your Strength Training Program

    People often focus on cardio for losing weight, but adding more muscle will really help you burn more fat.  Muscle is more metabolically active than fat so, the more you have, the more calories you burn all day long. Just a couple times a week is all you need to add lean muscle tissue and burn more fat.

    Lifestyle Factors

    Watching your stress levels and getting enough sleep are the keys to keeping your weight in check since stress hormones can contribute to weight gain. Taking care of yourself will make it easier to maintain the energy needed to complete key workouts and will help you to stay motivated to shop for and prepare nutritious foods. 

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