In general, body fat scales provide a rough estimate based on your weight and other factors.
If you’re exercising regularly, making healthy food choices, and not seeing the scale budge, it may be time to assess your body fat percentage.
When you’re trying to lose weight, measuring body fat is equally as important as measuring your overall weight.
That’s because healthy habits, like exercise, can build muscle. Increased muscle mass can make the number on the scale stay the same or, in some cases, increase, even if you’re losing fat and becoming more toned.
One way to assess your progress is to step on a body fat scale. While these aren’t the only methods of determining a healthy body weight, measuring your body fat can help you determine if your weight loss efforts are working.
If you’re not trying to lose weight, a body fat scale can still help you figure out if you have a healthy fat-to-muscle ratio.
Body fat scales aren’t completely foolproof, but they’re just some of the options to measure your body fat in between visits with your doctor or your personal trainer.
Body fat scales are easy to use. You simply step on the scale, and the tool measures both your body weight and your estimated fat percentage.
Such scales work with the help of sensors underneath your feet that use bioelectrical impedance. When you step on the scale, a small electrical current runs up through your leg and across your pelvis, measuring the amount of resistance from body fat.
Then, the sensors in the scale measure the level of resistance that the current met as it travels back through your other leg.
Depending on the type of body fat scale you have, the information can link up to your smartphone or smartwatch, as well as any fitness apps you might have.
As a rule of thumb, greater body resistance means a higher fat percentage. This is due to the fact that fat contains less water than muscle, so it’s more difficult for a current to travel through it.
In general, body fat scales can provide rough estimates only. While safe to use, there are many variables that can affect your results. These include:
- Your gender. Women naturally have more body fat than men.
- Where you store fat in the body.
- Pregnancy. These scales aren’t recommended during pregnancy.
- Your age. These scales
aren’t suitable for children. - Your height and stature.
- Frequent endurance and resistance training.
The greatest benefit to using this type of scale is that you can measure your body fat in the comfort of your own home at any time, all without having to travel to a gym or clinic.
However, these scales aren’t completely accurate. You don’t want to make them your sole measurement of your overall health.
Another drawback is that a body fat scale doesn’t take into account other variables of body fat, such as where you might have it.
For example, doctors tend to be more concerned about body fat that’s concentrated around your midsection because this can increase your risk for certain health conditions, like heart disease.
A body fat scale can only tell you the overall percentage and not where on the body you’re storing potentially dangerous fat.
Body mass index (BMI) is perhaps a more reliable indicator of your overall health instead of counting on a body fat scale alone. While BMI can’t measure fat, it does provide an overall picture of whether you’re in the right weight range for your height and age.
The
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal or healthy weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obese |
You can use online calculators to determine your BMI, such as
The downside to relying on BMI is that it doesn’t measure body fat. So, an athlete with a lot of muscle, for example, could have a higher BMI based on their weight and height.
Also, the CDC says that women, older adults, and people of Asian descent naturally have higher levels of body fat. All of these factors can limit the reliability of BMI as your sole measurement of health.
While stepping on a scale is perhaps the easiest method of body fat measurement, there are other ways you can determine your body fat percentage. Aside from BMI, you can ask your health provider about the following methods:
Waist measurements
One drawback to body fat scales is that they don’t tell you how much fat your body is holding around the waistline, which is considered a risk for:
- cardiovascular diseases
- type 2 diabetes
- fatty liver disease
Measuring your waistline can help complement your body fat scale results.
The
Calipers
Often used by fitness professionals, calipers are used to literally pinch your skin folds (usually around the waist or hips) to estimate your body fat.
The accuracy of this method varies. Results may be more or less accurate depending on the expertise of the person taking the measurement.
Dual-energy x-ray absorptiometry (DEXA) scans
Often used to measure bone mass for osteoporosis diagnoses, DEXA scans are also reliable methods of body fat measurement and can be more reliable than relying on BMI alone.
To get one of these scans, you’ll need to find a center that has the equipment. The scans can be pricey depending on your location and may not be covered by insurance.
Handheld fat measurement devices
This body fat measurement test works similar to that of a scale, except it doesn’t measure your weight. There are sensors on either side of the device that measure your body fat as you hold the device in front of you.
Handheld fat measurement devices aren’t as accurate as other methods, but they’re easy to use and relatively inexpensive.
Underwater weight (hydrodensitometry) test
This test is based on the buoyancy of your body weight. Fat floats more easily than muscle. Based on your buoyancy and your weight, the person administering the test can calculate your body fat percentage.
Underwater testing is considered to be an accurate tool for measuring body fat. However, it can be difficult to find a center that has the ability to do this type of testing. The test can also be uncomfortable.
Bod Pod
Available at some fitness centers and medical facilities, a Bod Pod is a device you sit in for a few minutes while it measures your body fat via air displacement plethysmography (ADP).
This method has similar accuracy when compared to underwater testing. However, access to these devices is limited, and testing can be expensive.
Body fat scales can be helpful when you’re trying to measure your body fat, but they don’t tell the whole story about your fat-to-muscle ratio. Instead, you can use these scales as complements to other tools.
Talk to your doctor about your BMI, and how you can best measure and track your body composition.
