The 6 Best Ways to Measure Your Body Fat Percentage
It can be frustrating to step on the scale and see no change.
While it’s natural to want objective feedback on your progress, body weight shouldn’t be your main focus.
Some “overweight” people are healthy, while others with “normal weight” are unhealthy.
However, your body fat percentage tells you what your weight is comprised of.
Specifically, it tells you the percent of your total body weight that is fat. The lower your body fat percentage, the higher percentage of lean muscle mass you have on your frame.
Here are the 6 best ways to measure your body fat percentage.
1. Skinfold Calipers
Skinfold calipers measure the thickness of your subcutaneous fat — the fat underneath the skin — at certain body locations.
Measurements are taken at either 3 or 7 different sites on the body. The specific sites used vary in men and women.
For women, the triceps, area above the hip bone and either the thigh or abdomen are used for the 3-site measurement.
For a 7-site measurement in women, the chest, area near the armpit and area beneath the shoulder blade are also measured.
For men, the 3 sites are the chest, abdomen and thigh, or the chest, triceps and area beneath the scapula.
For a 7-site measurement in men, the areas near the armpit and beneath the shoulder blade are also measured.
- Advantages: Skinfold calipers are very affordable, and measurements can be taken quickly. They can be used at home but are also portable.
- Disadvantages: The method requires practice and basic anatomy knowledge. Also, some people don’t enjoy getting their fat pinched.
- Availability: Calipers are affordable and easy to purchase online.
- Accuracy: The skill of the person performing the skinfolds can vary, impacting the accuracy. Measurement errors can range from 3.5–5% body fat.
- Instructional video: Here is an example of a 7-site skinfold assessment.
SUMMARYEstimating body fat percentage with skinfold calipers is affordable and relatively simple once you know how to do it. However, the accuracy depends on the skill of the person performing the assessment.
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2. Body Circumference Measurements
Body shape varies from person to person, and the shape of your body provides information about your body fat.
Measuring the circumference of certain body parts is a simple method of body fat estimation.
For example, the US Army uses a body fat calculation that simply requires an individual’s age, height and a few circumference measurements.
For men, the circumferences of the neck and waist are used in this equation. For women, the circumference of the hips is also included.
- Advantages: This method is easy and affordable. A flexible measuring tape and calculator are all you need. These tools can be used at home and are portable.
- Disadvantages: Body circumference equations may not be accurate for all people due to differences in body shape and fat distribution.
- Availability: A flexible measuring tape is easily available and very affordable.
- Accuracy: The accuracy can vary widely based on your similarity to the people used to develop the equations. The error rate can be as low as 2.5–4.5% body fat, but it can also be much higher.
- Instructional video: Here is a video showing examples of girth measurements.
SUMMARYUsing body circumferences to estimate body fat is quick and easy. However, the accuracy of this method can vary widely and is not considered an ideal method of measuring body fat percentage.
3. Dual-Energy X-ray Absorptiometry (DXA)
As the name implies, DXA uses X-rays of two different energies to estimate your body fat percentage.
During a DXA scan, you lie on your back for approximately 10 minutes while an X-ray scans over you.
The amount of radiation from a DXA scan is very low. It’s about the same amount you receive during three hours of your normal life.
DXA is also used to assess bone density and provides detailed information about the bone, lean mass and fat in separate body regions (arms, legs and torso).
- Advantages: This method provides accurate and detailed information, including a breakdown of different body regions and bone density readings.
- Disadvantages: DXAs are often unavailable to the general public, expensive when available and deliver a very small amount of radiation.
- Availability: A DXA is typically only available in medical or research settings.
- Accuracy: A DXA provides more consistent results than some other methods. The error rate ranges from 2.5–3.5% body fat.
- Instructional video: Here is a video showing how DXA works.
SUMMARYDXA is more accurate than many other methods of assessing body fat percentage. However, it’s often unavailable to the general population, fairly expensive and not feasible for regular testing.
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4. Hydrostatic Weighing
This method, also known as underwater weighing or hydrodensitometry, estimates your body composition based on its density.
This technique weighs you while submerged under water after exhaling as much air as possible from your lungs.
You are also weighed while you are on dry land, and the amount of air left in your lungs after you exhale is estimated or measured.
All of this information is entered into equations to determine the density of your body. Your body’s density is then used to predict your body fat percentage.
- Advantages: It’s accurate and relatively quick.
- Disadvantages: It’s difficult or impossible for some individuals to be fully submerged under water. The method requires breathing out as much air as possible, then holding your breath underwater.
- Availability: Hydrostatic weighing is typically only available at universities, medical settings or certain fitness facilities.
- Accuracy: When testing is performed perfectly, the error of this device can be as low as 2% body fat.
- Instructional video: Here is an example of how hydrostatic weighing is performed.
SUMMARYHydrostatic weighing is an accurate way to assess your body fat. However, it’s only available at certain facilities and involves holding your breath while being completely submerged in water.
5. Air Displacement Plethysmography (Bod Pod)
Similar to hydrostatic weighing, air displacement plethysmography (ADP) estimates your body fat percentage based on the density of your body.
However, ADP uses air instead of water. The relationship between the volume and pressure of air allows this device to predict the density of your body.
You sit inside an egg-shaped chamber for several minutes while the pressure of the air inside the chamber is altered.
To obtain accurate measurements, you need to wear skin-tight clothing or a bathing suit during testing.
- Advantages: The method is accurate and relatively quick, and it does not require being submerged in water.
- Disadvantages: ADP has limited availability and can be expensive.
- Availability: ADP is typically only available at universities, medical settings or certain fitness facilities.
- Accuracy: The accuracy is very good, with an error rate of 2–4% body fat.
- Instructional video: This video shows a Bod Pod assessment.
SUMMARYThe Bod Pod is the main ADP device currently used. It predicts your body fat with air rather than water. It has good accuracy, but it’s typically only available at certain medical, research or fitness facilities.
6. Bioelectrical Impedance Analysis (BIA)
BIA devices detect how your body responds to small electrical currents. This is done by placing electrodes on your skin.
Some electrodes send currents into your body, while others receive the signal after it has passed through your body tissues.
Electrical currents move through muscle easier than fat due to the higher water content of muscle (12 ).
The BIA device automatically enters your body’s response to the electrical currents into an equation that predicts your body composition.
There are many different BIA devices that vary widely in cost, complexity and accuracy.
- Advantages: BIA is quick and easy, and many devices can be purchased by consumers.
- Disadvantages: The accuracy varies widely and can be greatly affected by food and fluid intake.
- Availability: While many units are available to consumers, these are often less accurate than the expensive devices used in medical or research settings.
- Accuracy: Accuracy varies, with an error rate that ranges from 3.8–5% body fat but may be higher or lower depending on the device used (3,
13 ). - Instructional videos: Here are examples of inexpensive BIA devices with hand electrodes, foot electrodes and hand and foot electrodes. Here is an example of a more advanced BIA device.
SUMMARYBIA devices work by sending small electrical currents through your body to see how easily they travel through your tissues. Many different devices are available, although advanced devices produce more accurate results.
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Which Method Is Best for You?
Deciding which method of assessing body fat percentage is best for you isn’t easy.
Here are several questions that may help you decide:
- What’s the purpose of assessing your body fat percentage?
- How important is high accuracy?
- How often do you want to test your body fat percentage?
- Do you want a method you can perform at home?
- How important is price?
Some methods, such as skinfold measurements, circumference calculations and portable BIA devices, are inexpensive and allow you to be measured in your own home as frequently as you like. The devices can also be purchased online easily, such as on Amazon.
Even though these methods don’t have the highest accuracy, they may be the best choice for you.
Most of the methods with highest accuracies are not available to use in your own home. What’s more, when they are available at a testing facility, they may be expensive.
If you want a more accurate assessment and are willing to pay for it, you could pursue a method with good accuracy like hydrostatic weighing, ADP or DXA.
Whichever method you use, it’s important to use the same method consistently.
For almost all methods, it’s best to perform your measurements in the morning after an overnight fast, after you go to the bathroom and before you eat anything or begin your daily activities.
Ideally, you should do the test before you have anything to drink, especially for methods that rely on electrical signals like BIA, BIS and EIM.
Assessing yourself the same way each time will reduce error rates and make it easier to tell if you are making progress.
However, you should always interpret your results from any method with caution. Even the best methods are not perfect and only give you an estimate of your true body fat.