How Do Scales Measure BMI?


Exercise may help you live a healthy life. However, if you are exercise regularly, with a good healthy food intake, you should also know the fat percentage in your body. You must know whether your efforts are giving you the results you are looking for better overall health.

If you are exercising with an aim to lose weight, it becomes a prime objective to check on your body fats. This should be done while counting in your overall body weight.

However, before that, you should know your BMI.

See Related: BMI Scale Calculator

BMI Measuring Scales

What they Do and How they Work

BMI scales requires that you input the user's height.

It then measures the weight and runs the BMI calculation to give you your BMI number based on height and weight.

These scales also measure body fat percentage.  Once you step on this scale, it will calculate your body fat percentage with the help of sensors underneath your feet.

These sensors work on a bioelectric method. These scales use passing electrical current up to your legs and the pelvis area. This measures the amount of resistance from your body fats.

The sensors, in return, will measure the level of resistance the current will meet on its way back through your other leg –the greater the body resistance, the higher the fat percentage.

You may observe that fat contains less water than muscles, so it’s denser than muscles. Hence, fats make it difficult for electric current to pass through. 

You may find different BMI scales for keeping track of your body mass. Here are the two best products:

What is BMI?

Body mass index or BMI is a method to measure body weight adjusted for height. It is calculated as weight in kilograms divided by the square of your height in meters.

Thus, its unit is kg/m2. While many people think BMI is an indicator of body fatness, it is a surrogate measurement of your body fats as it measures your excess weight instead of excess fats. Nonetheless, the results may be 5% off, high or low.

BMI - Body Mass Index

As a thumb rule, BMI has the following set of calculation results:

  •  BMI less than 18.5 shows you are underweight
  •  BMI between 18.5 and 24.9 means your weight distribution is good and possesses no potential health risks
  •  BMI between 25 and 29.9 shows you are overweight and prone to health risks. You should consider losing weight.
  • A BMI equal to or more than 30 puts you in the obesity level and is a potential health risk situation. A drastic weight loss exercise method may be your requirement to shed off obesity.

What Pain are we solving and problems are we avoiding? 

The foremost problem using BMI scales is they may be off 5% more or less and you may not get accurate readings. It may not give you hydrostatic data about muscle mass, bone density, bone mass, etc. 

Nonetheless, BMI scales help you dial your fitness goals at a glance. 

This leads to a low risk for joint and muscular pains. Its regular use will give momentum in body fluids and keep blood pressure normal; thus, reducing your heart disease risks. It may also help you regulate your sleeping pattern.

Body fat vs. BMI

BMI deals with approximate body fat by using a mathematical formula. In contrast, body fat percentage will give you a clear difference for fat from muscles and calculates the total percentage of your body fats.

Logic for using one vs. the other

BMI gives you a quick, methodical approach to understand your body status. Its bioelectrical impedance is a brilliant procedure to identify whether you are within the weight limit, overweight, or obese. Its benchmark reading is there for you to attain those levels. 

In sharp contrast, body fat percentage will describe the excessive fats without elaborating its extreme ends to reach safe levels.

FitTrack Dara Smart BMI Digital Scale 

It’s the most accurate Bluetooth Glass Bathroom Scale, and measures weight and body fats. FitTrack’s Dual BIA Technology uses dual frequencies to find 17 different measurements of your body to assess your body mass index (BMI), muscle mass, and obesity level.

Its other features are:

  • 8 different users can use the device
  • It recognizes each individual and tracks results, including your baby’s, while keeping the result private from other users.
  • An app for both iOS and Android users, FitTrack Pro, will save your measurements on your smartphone devices. It tracks your body measurements in a chronological sequence and reminds you about weigh-ins frequently.
  • FitTrack weight management will keep you abreast about your lifestyle, diet plan, and other relevant aspects which can affect your health.
  •  Its Athlete and infant variant modes enhance its impact for all kinds of users.
  • FitTrack Dara Smart BMI Digital Scale runs on award-winning technology. Its precise weighing mechanism ensures complete and most accurate body measurements.
  •  It’s a battery-powered BMI scale.

When you use the FitTtrack scale, a low and safe electric signal runs through your feet. It passes through water in hydrated body muscles and faces resistance while countering fats or tissues. This resistance is what comes into calculations into its scientifically validated FitTrack mathematical equations to compute your body configuration measurements.

FitTrack Beebo Family Smart Scale

It’s a smart innovation for moms-to-be and the baby during and immediately after pregnancy. It tracks the health of the baby and the mom simultaneously.

When you mount this scale as per mode setting, FitTrack Beebo will deduct mom’s weight to give you a better insight into your baby’s health and growth.

This device will track the health measurements of 8 users, securing their data in private from one another. It can carry weight up to 400 lbs.

Beebo Family Smart Scale tracks your baby’s growth using 17 health measurement factors.

Beebo Smart Scale’s maternity mode will offer four options, including infant, pregnancy, athletic, and general modes. It will give measurements in 17 different health metrics.

It’s more like a family smart scale. In addition to calculating your BMI and weight, it also measures your muscle mass, obesity variation, hydration, and more.

While using it, you will feel nothing. The electric current counters water, abdominal fat and muscle tissues; these muscle tissues resist the electric current.

This impedance, in return, is calculated in FitTrack Beebo Smart Family Scale built-in equation to give your measurement, including body fats level.

How Accurate Are BMI Scales?

Accuracy vs. Precision

Body fat scales use BIA (bioelectrical impedance analysis) to evaluate the relative percentage of tissues and substances in your body.

These scales use a mathematical formula considering a person's age, height, weight, and gender. Modern scales can get such information through smartphones or other electronic devices. Mostly their accuracy is 5% more or less. Your activity level can also impact your BMI.

Body Composition

It’s a reference to different substances in your body, like fat proportion, lean tissues, muscles, body water, organs, etc. This measurement will define clear indicators of your fitness level.

Why Own A BMI Scale

Owning a BMI scale will allow you to keep check on your body mass index, body composition, body fat percentage, and possible health problems that you may possess. BMI scale is like a pre-alert tool to avoid health hazards. You can avoid heart disease, type 2 diabetes, to name a few, by tracking your BMI.


Whichever BMI scale or fitness method you may use, do it persistently to get the best results. It’s ideal if you perform measurement methods early morning before having anything to drink, especially those that use electrical signal methods.

However, you may be careful while interpreting your results from any method. Sometimes, these methods may not give you accurate and precise results. These metrics are for your wellness.