How to Calculate Body Fat Percentage

There are different ways to calculate your body fat percentage. Some methods require special equipment or access to expert services. These methods are recognized as being the most accurate.

You can also estimate body fat percentage at home. A body fat calculator is the easiest method because it requires no special tools or lengthy appointments with a specialist.

This method will estimate your body fat percentage, which you may confirm with other methods. You'll need a basic tape measure and about five minutes to gather the data you need for an instant body fat measurement.

⁣How to Use the Body Fat Calculator

There are a few best practices to keep in mind when figuring out how body fat is calculated. Follow these guidelines for calculating the most accurate body fat percentage.

When to Take Body Fat Measurements

You'll want to take measurements first thing in the morning to get the most accurate result. 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 your numbers. Do not use an elastic tape measure. A measuring tape like what a tailor uses is optimal.

How to Take Your Body Fat Measurements

When you measure the circumference of each body part, the tape should feel firm enough against your skin so it stays in place. However, it should not be so tight that it causes an indentation. You can use either imperial or metric units. 

The measurements that need to be taken are slightly different for men and women. Men only measure waist circumference, but women also measure other parts of the body, including the hips, wrist, and forearm.

Men

• Current weight. Use a digital scale if possible.
• Waist circumference. Measure the largest part of your belly, usually right at the level of your umbilicus (belly button). Make sure that the tape measure stays level with 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. Measure the largest part of your belly, usually right at the level of your umbilicus (belly button). Make sure that the tape measure stays level with 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 (where your butt extends back).
• Forearm circumference. Measure around 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 percentage compares with other men or women in various categories. There are five ranges or body fat categories, according to the American Council on Exercise (ACE). Keep in mind these categories are based on body fat norms and may not indicate your specific level of fitness or health.

Links to Disease Risks

It is problematic to assign a strict cut-off for what body fat percentage puts someone at higher risk of health concerns like heart disease, diabetes, and stroke. Body fat percentage as a standalone figure does not account for gender, ethnicity, or age differences.

Other measurements may help you evaluate your risk for conditions like cardiovascular disease. If your body fat is too high according to the calculator, speak to a 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 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 carry 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?

Why does body fat percentage matter? If your goal is weight loss, you might be tempted to use a simple bodyweight scale for feedback on your progress, but your body fat percentage will tell you more than the scale.

When your goal is weight loss or to increase your 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. Lean mass includes bone, blood, connective tissue, organs, and muscle.

Muscle loss can occur when you lose weight, but it's not the kind of weight loss you seek. You want to maintain muscle mass because it helps your body to function and perform more efficiently, boosts your metabolism, and can help improve glycemic control.

By measuring changes in body fat percentage, you can gauge 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 ways to measure body composition (or the amount of fat and lean mass). Using a body fat calculator is just one.

One method for measuring body fat percentage won't be appropriate for everybody. For example, if you would be uncomfortable going underwater, you would not want to attempt hydrostatic weighing. Each method also has its 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 body fat percentage. The formula is slightly different for men and women. 

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

• (Total bodyweight x 0.732) + 8.987

The tool uses fractions of each body measurement to estimate your body fat percentage.  

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

• (Total bodyweight x 1.082) + 94.42

The tool uses a fraction of the weight measurement to estimate body fat percentage.

A body fat calculator is not the most accurate measurement of body fat percentage. However, it's the most accessible system to use. Therefore, you may be able to use it more often.

Measuring at the same time each day and using the same tools (tape measure and online calculator) allows you to track trends in your progress, which can be far more valuable in assessing your fitness gains than a standalone body fat percentage measurement.

Skin Caliper Measurements

Several body fat calculators use skinfold measurements instead of body circumference measurements to estimate your body fat percentage. Skinfold calipers can be purchased to use at home, or you can hire a professional who is skilled in using them in healthcare or gym settings. It's one of the more popular devices to monitor body fat.

Skin calipers pinch a portion of your body to estimate fat levels. The caliper method can be more accurate than a calculator for measuring body fat percentage, but the accuracy depends on the skill level of the person using them.

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

Whole-body scanning is quickly becoming the gold standard for measuring body fat percentage. However, the main reason the test is so accurate is that it is generally performed in a medical setting by highly skilled technicians. The DeXA test is often costly and may not be available where you live.

Hydrostatic Weighing

This submersion method has long been recognized as the most accurate measurement of body fat percentage. However, it requires a person to be fully immersed in a tank of water while holding their breath.

For many, the endurance required for hydrostatic weighing can be a challenge. It can also be difficult to find a location that performs the test.

How to Reduce Body Fat

Because thinness has so much value in many cultures, many people want to lose weight at some point. However, reducing body fat should not be a goal for everyone. Speak with a healthcare professional before starting a weight-loss program. It's also important to know that these numbers don't apply to pregnant women—you should not try to lose weight during pregnancy.

You'll also want to talk to a healthcare provider if you are trying to lose weight while on medications or during cancer treatment to ensure that it is safe. If your doctor determines that reducing your body fat percentage is a safe and beneficial health goal, here are some areas for you to consider making changes.

Your Diet

How much you eat and what you eat are significant factors in losing or gaining body fat. You might be tempted to try a popular diet, but fad diets generally don't work. What does work is making small lifestyle changes, such as:

• Reducing your portion sizes.
• Eating smaller meals more frequently throughout the day and avoiding the urge to skip breakfast.
• Ensuring your diet contains lots of fruits and vegetables to fill you up and give you the necessary nutrients.
• Adding more fiber to your diet to keep you full.
• 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 ensure it's the right cardio. Make sure you include high-intensity interval training in your program up to two to three times per week. In addition to cardio, you should also incorporate moderate and easy workouts.

Your Strength Training Program

People often focus on cardio to lose weight, but adding more muscle will help you burn more fat. Muscle is more metabolically active than fat, so the more you have, the more calories you burn all day. Strength training a couple of 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 help you stay motivated to shop for and prepare nutritious foods. 

A Word From Verywell

There are other methods of measuring body fat not listed here. Whichever way you choose, remember that if you plan to measure your body fat regularly, you need to use the same method each time to get the most accurate data.

If you want to change your body fat composition, a balance of nutritious eating and being sure to avoid fad diets, coupled with exercise, is the best bet. Consult a healthcare provider to assess your health risks and make a plan for staying healthy.