How Do Smart Scales Work? Are They Accurate?

The new smart scale technology might seem a little intimidating, confusing, exciting, or a mix of all three!

Smart scales use Bioelectrical Impedance Analysis to determine your body fat percentage, muscle mass, and other data points. Smart scales are not medical-grade precision instruments, but they can be used to estimate body composition and track trends over time.

Here is an outline of all the technology that goes into a smart scale and some insight into how much you can actually trust the readings.

Smart Scale Technology

Smart scales work by using various technologies to measure not only your weight but also other body composition metrics, such as body fat percentage, muscle mass, bone density, and water weight.

Like traditional scales, smart scales begin by measuring your weight. This is done by applying pressure to the scale’s surface, which is usually equipped with sensors, such as strain gauges or load cells. These sensors detect the amount of force exerted on the scale, which is then converted into a weight measurement.

One of the things that makes these scales “smart” is Bioelectrical Impedance Analysis (BIA). Many smart scales use BIA to estimate body composition. BIA works by sending a low-level electrical current through your body when you step onto the scale.

This current flows more easily through tissues that contain a higher percentage of water (like muscle) and encounters resistance in tissues with less water (like fat). The scale measures the resistance, and using algorithms, it estimates various body composition metrics.

To facilitate BIA, smart scales often have multiple electrodes on their surface. These electrodes send and receive the electrical signals that pass through your body. By analyzing how the electrical current travels between these electrodes, the scale can estimate the distribution of water, fat, and muscle in your body.

The scale’s built-in processor or a connected smartphone app processes the raw data from the weight measurement and BIA. Advanced algorithms are then applied to calculate body fat percentage, muscle mass, and more.

Smart scales typically display the weight and additional metrics on a built-in screen. They also have the capability to sync this data with a companion smartphone app via Bluetooth or Wi-Fi. The app provides a user-friendly interface to view, track, and analyze your health metrics over time.

In some cases, the data collected by the smart scale may be uploaded to cloud storage, allowing you to access your health data from multiple devices and ensuring that you don’t lose your data even if you change phones or devices.

Many smart scales support multiple user profiles. To ensure accurate tracking for each user, these scales often have features that recognize users based on previous measurements. When you step onto the scale, it may identify you by comparing the measurement data to the profiles stored in its memory.

What Influences The Accuracy Of The Scale?

smart scales

The accuracy of smart scales can vary significantly depending on several factors, including the brand and model of the scale, the technology used for measurements, hydration levels, skin temperature, and how well the scale is calibrated and maintained. Here are some considerations regarding the accuracy of smart scales:

  1. Technology Used: Smart scales typically use bioelectrical impedance analysis (BIA) to estimate body composition. BIA measurements are generally considered reasonably accurate for estimating trends and changes in body composition over time. However, BIA measurements can be influenced by factors like hydration levels, skin temperature, and the distribution of fat and muscle in the body. The number and quality of electrodes may affect accuracy.
  2. Hydration Levels: Hydration plays a significant role in BIA measurements. Changes in your hydration status, such as being more or less hydrated than usual, can impact the accuracy of the measurements. The electric current flows more easily through materials with plenty of water. If you are well hydrated, your muscle reading may be slightly higher than accurate. If you are dehydrated, your body fat percentage may be slightly higher than accurate.
  3. Temperature: The temperature of your home can affect BIA measurements. Some smart scales attempt to account for this, but it is not perfect. Cold air causes the mechanisms inside the scale to contract slightly, creating small inaccuracies. You can opt for models that try to account for temperature fluctuations.
  4. Calibration: The accuracy of a smart scale depends on how well it is calibrated. High-quality, well-calibrated scales tend to provide more accurate measurements. Some smart scales require periodic calibration to maintain accuracy. Make sure you read up on the owner’s manual to make sure you are calibrating correctly. This will give you the most accurate readings.
  5. Model and Brand: Different smart scale models and brands may vary in terms of their accuracy. It’s essential to research and read reviews to identify models known for their accuracy.
  6. User Variability: The accuracy of smart scales can vary from person to person. Individuals with unique body compositions, such as athletes or people with medical conditions affecting their hydration levels, may experience less accurate measurements.

Smart scales can provide useful and relatively accurate estimates of body composition for many individuals. However, they may not be as accurate as more specialized and expensive methods used in clinical settings. Smart scales provide valuable insights into your body composition, but they should be viewed as estimation tools rather than highly precise medical devices.

While smart scales may not provide medical-grade accuracy, they are often consistent in their readings. This means that if you use the same smart scale under similar conditions over time, it can still be valuable for tracking trends and changes in your body composition.

The key is to focus on trends and relative changes rather than placing excessive importance on single measurements.

If you have specific health concerns or require highly accurate measurements, it’s advisable to consult with a healthcare professional or use more precise measurement methods.

Tips For Selecting An Accurate Smart Scale

smart scales

While we know that smart scales are not perfect, following these few tips will help you get the most accurate readings possible. Smart scales can be a great tool when used and cared for properly.

When selecting a smart scale to buy, do a little research to make sure it is a good model.

Start by reading user reviews and expert reviews of the smart scale models you’re considering. Look for feedback from people who have used the scale over an extended period, as this can provide insights into its accuracy and consistency.

Research the reputation of the brand or manufacturer. Well-established brands with a history of producing quality health and fitness products are often a safer bet in terms of accuracy.

This scale from GE is from a reputable brand and has great reviews.

Some smart scales may have certifications or approvals from health and fitness organizations or regulatory bodies. These certifications can indicate that the scale meets certain accuracy and performance standards.

Seek recommendations from friends, family, or colleagues who use smart scales. They may have firsthand experience with a particular model’s accuracy.

Check the return policy of the retailer where you plan to purchase the smart scale. Ensure that you have the option to return or exchange the scale if you find it to be inaccurate or unsatisfactory.

Once you have a smart scale you like, you can do a few things to test its accuracy and get a baseline of what our measurements should look like.

To assess the accuracy of your smart scale, you can compare its measurements to those taken by other methods, such as skinfold calipers, dual-energy x-ray absorptiometry (DXA) scans, or hydrostatic weighing, which are considered more precise but may not be as convenient or accessible.

If possible, compare the measurements provided by the smart scale to those from a traditional, reliable bathroom scale that you trust. This can give you a rough idea of how the smart scale compares in terms of weight measurement.


Empowering minds and bodies through my fitness journey! Passionate fitness enthusiast and blogger on a mission to inspire and motivate. Transforming lives one post at a time with evidence-based workouts, nutrition tips, and a sprinkle of wellness wisdom. Join me on this sweaty adventure to unlock your full potential and cultivate a balanced, healthy lifestyle. Let's break a sweat, embrace the grind, and celebrate the victories together! ✨ #FitLife #WellnessWarrior #FitnessBlogger"

Recent Posts