Body Fat Percentage Calculator (Complete Guide)

how to calculate body fat percentage

The body fat percentage is calculated based on the amount of fat you have in your body compared to the amount of body your muscle, organs, water, tendons, and whatever else is going on in there takes up [1]. It’s not an easy thing to calculate accurately but for anyone who wants to improve their overall health, understanding your body fat percentage and keeping it within healthy ranges is a great measure of healthiness.

Everyone must have some body fat to stay alive. Some fat is called “brown fat” and is mainly in our neck and around the blood vessels of our thorax. The brown fat helps keep our bodies warm if we are in severely cold temperatures.

If you weigh 200 pounds and have 20 pounds of fat, your body fat percentage is 10% (20 divided by 200). When you gain and lose fat, your body fat percentage will fluctuate.  Your body fat percentage will also change as you gain or lose muscle.

You Can Be “Overweight” But Not Have Too Much Body Fat

Sometimes people are classified as being “overweight” based on the number on the scale or their BMI. Just because someone is overweight does not automatically mean they are carrying around too much body fat, however. Muscle actually weighs more than fat, so people who are athletic and build strong muscles can technically be overweight in terms of the appropriate number of pounds for their height, but not have too much body fat. That is why BMI or the number on the scale are not the best methods for determining whether or not you’re healthy, and calculating your body fat percentage is a better way to determine whether your weight is in a healthy range or not [2].

Calculating BMI is Not the Same as Body Fat

Even though most medical professionals will use your body mass index (BMI) to determine your level of health in terms of weight, it’s not directly correlated to your actual body fat percentage. The BMI is calculated based on your height and weight, so whether you have 200 pounds of pure muscle or 200 pounds of pure blubber – your BMI would give you the same number [3].

You can also be “skinny fat” but have a healthy BMI. This is a condition where you look thin, but you are carrying around too much body fat to be healthy.

BMI is calculated by dividing your weight in kilograms by your height in meters squared.  So, stand on a scale and get your weight in pounds. Let’s say it’s 200 pounds. Then to get your weight in kilograms, you multiply it by .45.

200 x .45 = 90 (kilograms)

Then, take your height in inches and multiply it by .025 to get your height in meters. Let’s say you are 74 inches.

74 x .025 = 1.85 (meters)

Next, we need to get the square of your height in meters.

1.85 x 1.85 = 3.4225
Finally, divide your weight in kilograms by your height in meters squared. In our example:

90 / 3.4225 = 26.2 (BMI)

If this is too much math for you, just use an online BMI calculator such as this one from the National Heart, Lung, and Blood Institute.

Here are the recommendations for BMI in terms of body weight status:

BMI under 18.5 means you are underweight.  Normal weight falls between 18.5 and 24.9 BMI. People with BMI between 25 and 29.9 are considered overweight, while anyone with a BMI of 30 or more is considered obese.

So in our example, a BMI of 26.2 means that person is overweight. But we have no idea how much of that weight is muscle and how much is fat. So it really doesn’t help us determine anything useful in terms of a healthy weight measurement. It’s okay for analyzing the entire population and setting up some general guidelines, but if you want to access your individual fitness level, you should use your body fat percentage instead.

Body Fat Differences for Men and Women

male and female body fat differencesWhen determining a healthy body fat range, you must take into consideration whether you are male or female. Women carry larger amounts of body fat than men in general, and that’s healthy and normal. Gender plays a role in how much fat we should have. For example, take a male and female competitive body builder, both who are super ripped and in the best shape of their lives. The male may get his body fat level down to 3% while the female may only get her body fat percentage down to 8% – both they are comparable fitness levels [4].

What Should My Body Fat Percentage Be?

If you’re not a competitive body builder but want to get your body fat percentage within healthy ranges, you may wonder what that range is. While most people don’t find fat attractive, it does serve a purpose in our bodies and we must have some body fat to protect our organs, help maintain body temperature, and produce hormones and chemicals our bodies require to function.

Body Fat Percentages for Men [5]

  • Essential Body Fat: 2 – 4%
  • Athlete: 6-13%
  • Fit: 14-17%
  • Normal: 18-25%
  • Overweight/Obese: 26% or more

Body Fat Percentages for Women [5]

  • Essential Body Fat: 9-11%
  • Athlete: 14-20%
  • Fit: 21-24%
  • Normal: 25 – 31%
  • Overweight/Obese: 32% or more

Only advanced bodybuilders should even attempt to get into the essential body fat ranges as you can become ill if you don’t know what you’re doing and try to reach that level of body fat. Being too thin can result in failing organs or hormone imploding and recovering from such events can take a long time.  To get the shredded, muscular appearance you’re probably looking for, you should focus on getting your body fat percentage into the lower ranges of the athletic category.

It’s easier to get into that body fat range than it is to maintain it for long periods of time. Even competition body builders get themselves into the low end of the athlete body fat range for a competition, only to find themselves with higher body fat percentages a week or two after the competition ends. Maintenance requires strict calorie control and eating the right diet for your body, and you are likely to fight against your body’s natural set point.

The fit body fat percentage range is totally healthy and will result in an athletic looking body, but it will lack the definition and “ripped” appearance found in the lower body fat percentage levels.

How to Get an Accurate Body Fat Percentage Reading

There are different methods of calculating your body fat percentage and all will give you different results which makes you wonder how accurate any of them are if they all give a different percentage!

Online Body Fat Calculators

First, you can use an online body fat percentage calculator.  This is probably the least accurate method as you simply input measurements of various body parts along with your weight and the calculator estimates what your body fat percentage is based on the numbers you enter [6].

Scales and Handheld Device Body Fat Calculators

body fat scaleA slightly more accurate method of calculating body fat is with a scale or handheld device. Through “bioelectrical impedance analysis” (BIA), your body’s resistance to a light electrical current is measured in order to calculate the percentage of body fat you have. Muscle is over 70% water and so it conducts electricity much better than fat, as fat holds less water than muscle. The higher the resistance to electrical current your body has, the fatter it must be… in theory.

The problem with handheld devices and scales used to calculate body fat using electricity is that as the current moves through your body, electricity takes the easiest path possible. That means it will travel through your internal tissues instead of the subcutaneous fat. Also, some of these scales skip parts of your body, which skews the results. So when standing on a foot scale, your torso isn’t factored into the calculation. When holding a handheld device, most will not calculate your body’s lower half. The results are simply not reliable when only a portion of your body is used to calculate your body fat percentage.

Other problems with BIA calculations of body fat percentages is that it relies on hydrostatic weighing mathematical equations which have been shown to be off by as much as 6% due to variations in hydration status, ethnicity, and body weight. For example, if you test your body when you haven’t had enough water your body fat percentage will be higher than it should because you have lower electricity conductivity when you are dehydrated.  Also, if you work out immediately before testing your body fat percentage, you can get an artificially low reading because your body tends to conduct electricity better right after a workout.

Skinfold Testing with Body Fat Calipers

You can calculate your body fat percentage using a tool called “calipers” to measure the thickness of skin at various points of your body.  The skinfold test involves adding the different measurements together and putting the numbers through equations to figure out your body fat percentage [7].

The problem with skinfold testing is if you can’t guarantee a “perfect pinch”. If you don’t pinch enough, you’ll get a lower body fat reading than you actually are. If you pinch too much skin, you’ll get a higher reading.  Studies have shown skinfold testing with calipers can be off as much as 10 to 15%.
If you are using calipers to track body fat percentages over time, however, the method becomes more accurate and can give you a good idea of where your body fat percentage falls. Your weight fluctuates daily, so you don’t want to read the number on the scale or use calipers on a daily basis and try to understand if you are going up or down in fitness from day to day, but you can obtain the most accurate averages by calculating every seven to ten days. Weigh yourself and do a skinfold test every morning at the same time and record your numbers. Every seven to ten days, add your daily weights and divide by the number of days, and calculate your body fat percentage and divide by the number of days to get your average weight and body fat percentage. If the number is higher over the seven days than it was the previous seven days – you’re gaining weight or body fat. If it’s lower, you’re losing weight or body fat.  Keep an eye on your average and don’t worry about the daily ups and downs that are temporary.

Non-Scientific Methods of Calculating Body Fat

If you just want a visual method of determining if you’re gaining or losing body fat, you can take a measurement of your waist using a simple measuring tape around your navel and compare it from one week to the next. An expanding waist line is a reliable method of fat gain while a shrinking one indicates weight loss. You can’t calculate your actual percentage of body fat with this method, but you can keep an eye on weight gain that is sneaking up on you by taking weekly waist measurements.

Another way to see whether you’re gaining or losing weight is by taking weekly photographs. You can look in the mirror every day, but it’s hard to see the gradual changes. When you have photographs, you can compare one week to the next to see if you notice any changes. Take photos wearing the same outfit, in the same room, with good lighting. It’s a good idea to take a picture from the front, side, and back to track your progress and help you stay motivated.

How to Control Body Fat

You can “learn” how to reduce or control body fat everywhere you look online or on every late night infomercial on the television. But most of these recommendations are just gimmicks designed to make the advertiser money. You can reduce body fat or maintain your level of body fat with a healthy diet, the right exercise, and some help from a high-quality fat burning supplement – Cinerate.

Even though you want to lose excess body fat as quickly as possible, the only proven method of losing body fat and maintaining the loss is to make long-term lifestyle changes. Intensive, “lose weight fast” type solutions aren’t really solutions at all. Most simply help you lose water, which will bring the number on the scale down, but not help you lose body fat at all.  Instead, use Cinerate according to the directions, focus on eating a healthy diet of lean meats and vegetables while reducing your starchy carbohydrate intake, drink lots of water, and exercise regularly. Both excess carbohydrates and excess sugar are stored in your body as fat. If you have a sweet tooth that won’t leave you alone, replace your candy or other sweets with fruit to satisfy the craving without overloading our body with calories and sugar.

Studies have shown that high-intensity exercise for short bursts of time followed by a period of rest is one of the best and most effective methods of burning fat. So you might get on the treadmill and walk at a reasonable pace for three minutes, then follow it with two minutes running, and return to a comfortable walk for three minutes for example.

The important thing to understand about body fat percentages is that they aren’t all that important or accurate if you just do it one time to get a reading. You need to take body fat calculations on a regular basis to see how they’re changing over time. This is how you determine if you are moving in the right direction health-wise, or if you need to make changes in your diet or exercise routine to get the results you’re looking for.

Instead, use the combination of your weight, your BMI calculation, your body fat percentage calculations, the measurements of your waist, and photographs over time to get a complete look at what’s going on with your body and the results you’re achieving.


  1. The Relationship Between Body Fat Percentage and Body Mass Index in Overweight and Obese Individuals in an Urban African Setting
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