What smart bathroom scale to buy? Shopping guide and featured models

smart bathroom scale

Bathroom scales are the nth gadget that has become intelligent, although this meaning should refer to something more than sending the weight to the mobile. With these devices we can know parameters such as BMI, body fat, history, add profiles … that help us to know in detail how our body is to help us stay fit or lose weight.

This purchase guide analyzes what features can be found in the smart scales that are in the market and the most prominent models.

How an intelligent scale works

The intelligent scales are simply bio impedance scales to which some connectivity has been incorporated, accompanied by an application that allows to see graphically the parameters and the evolution from a device.

As for connectivity, it is usual to have Wi-Fi and / or Bluetooth to communicate with tablets and smartphones and even with ANT +, to synchronize with other sports instruments (sensors, pedometers, watches with GPS).

Smart scale = bioimpedance scale + Connectivity

Bioimpedance scales use the electrical properties of the human body, the composition of their tissues and the amount of water present to obtain our fat mass.

While the water present in muscles, bones and blood vessels is a good conductor of electricity, fat is not. With this clear, the scale sends an electrical signal to our body through an input electrode and picks it up with another output, measuring the time required to pass through it.

We must bear in mind that muscles have a water content that is practically constant and equal to approximately 73%, so the time taken will determine the content of a person’s fat mass.

In a person with a lot of fat, this tour will be done more slowly and in a leaner one it will be faster.

Actually, what the scale calculates is our weight and lean mass, whose difference will be the amount of fat mass of a person.

However, not all bodies are the same, so the results should take into account age, sex or physical condition.

The bioimpedance is an approximate and acceptable method of measurement at home and amateur sports, however we must follow some indications when weighing to improve accuracy as not having eaten in the previous hours and have not done intensity sports on the day previous.

If we seek maximum precision as is the case of professional athletes, what is used is the measurement of skin folds using the caliper, a method that should always be done by a professional.

smart bathroom scale

Characteristics of smart scales

Knowing how an intelligent scale works, we already know that the only thing it measures is our weight and the amount of water through electrical bioimpedance, which allows us to estimate lean mass and fat mass.

The minimum essential that a scale must provide us both on its screen and in the application is the weight and the amount of body fat, which is displayed either as a percentage or in kilograms.

In fact, body fat is more important than weight to know how healthy we are, being a more reliable metric than BMI (body mass index, we will see below) to know if there is overweight, underweight, obesity or if we are in normopeso, since it differentiates the fat of the body against bone matter, muscle mass or viscera.

From here, each scale can provide other parameters calculated based on these two measurements and other personal information that we enter (such as age, sex or height) and contextualize them to give us an idea of how healthy our body is. That’s why profiles are so important.


Profiles are a key tool in our experience with an intelligent scale. We are not referring only to save different users, but to the scale allows us to differentiate if we are men or women, athletes or sedentary … And is that every age and lifestyle has some needs, so it is essential that a scale Smart has a guide that relates the parameters obtained based on gender, age and activity levels that are healthier and less for each percentile.

The result? Measurements that do not correspond to the reality of the person. Women’s bodies generally have more fat than men’s and athletes can weigh more for the amount of muscle, but their fat percentage is lower. Similarly, over the years the percentage of fat tends to increase in adults.

Therefore, to correctly evaluate the amount of fat in a body we have to consider its age, sex and level of activity. That’s why an active young woman can have the same weight and fat as a sedentary 60-year-old man, but it does not mean the same thing.

smart bathroom scale

Other metrics provided

With the profiles of each user and the measurements made, the intelligent scales can provide metrics obtained from calculations, tables and approximations, such as:

  • The kilograms or percentage of muscle mass, from the electric bioimpedance.
  • The percentage of body water, also from bioimpedance and taking into account that statistically it is 45-50% in women and 55-60% in men.
  • The body mass index, a parameter that relates weight and height used to identify overweight and obesity in adults approximately. It is calculated as the quotient between the weight in kilograms and the height in meters squared.
  • An approximation of your visceral fat. Visceral fat is one that is in the area of the abdomen and surrounds the internal organs that are there. The measurement of visceral fat accumulation is used to assess the risk of metabolic diseases. Taking into account that is measured with the perimeter of our waist, related waist and hip perimeters or waist / height index, it is an approximation.
  • The basal metabolism is the energy that your body consumes during a normal day to satisfy its vital functions, which is why exercise is excluded. That is, they are the calories needed to perform the vital functions of your body. It usually covers 70% of the total calories consumed throughout the day.
  • The metabolic age is the quantification in years of the level of wear of our body at the physiological level. Metabolic age differs from real age, so that a person who has led a healthy lifestyle may have a lower metabolic age than someone who was born in the same year. To obtain it, bioimpedance data (fat mass, lean mass, visceral fat, bone density, biological age and calculation of basal metabolism) are used and the more complete it is, the more accurate the calculation will be.
  • The muscular quality, evaluating the density of muscle fibers. Thus, a high quality muscle has low fatty connective tissue and a low quality muscle has high connective tissue, more fatty, and with lower density of muscle fibers.

Xiaomi Mi Scale 2

smart bathroom scale

One of the most affordable and complete smart scales in the domestic range is the Xiaomi Mi Scale 2, a device that also complements the health ecosystem of the Chinese brand with the wearables Mi Band and Amazfit.

However, if you do not have the activity wristband or the Xiaomi smartwatch, nothing happens, since it will be enough to install the Mi Fit app on iOS or Android to synchronize it with other activity meters.

The good thing about Mi Fit is that it allows you to create a profile with your age, sex and weight and exercise objective, however you do not have an athlete mode that evaluates how your body is in that case.

The Mi Scale 2 offers 10 parameters : weight, muscle mass, bone mass, basal metabolism, BMI, amount of water, visceral fat, percentage of fat, figure and body score, a metric that places you according to your BMI in a graph of other users that you should not give much importance.

This scale has 4 electrodes and Bluetooth and Wi-Fi connectivity, is made of ABS with an ultra-thin design with rounded edges to avoid hurting our fingers, with hidden LED screen. On eBay for 36.95 dollars.

Huawei Smart Scale

smart bathroom scale