How to get the most accurate smart scale readings 

Smart scales aren’t perfect, but our tips will help you get the most out of them.

If you’re considering using smart scales to help keep track of your health and fitness goals, it’s important to try to ensure you have the most accurate smart scales readings.  

There are many different smart scales and body composition monitors on the market, which not only measure weight but also body mass index, body fat percentage and basal metabolic rate (BMR). Each of them promises accurate readings and a variety of features to help you track your health. 

But if you aren’t using your smart scales properly, you may find that readings are less accurate than they could be, making it harder for you to see whether what you are doing is having the desired effect in terms of either your weight or your body composition.

A person standing on a Withings Body Cardio body composition smart scaleCredit: Withings

We’ll explain what you need to do in order to get the most accurate smart scale readings possible. Once you have confidence in the numbers, you’ll be in the best possible position to decide what lifestyle changes you want to make.  

If you want to minimise the variability of your readings, there are a few tips to follow to ensure that you are getting the most accurate and consistent readings possible from your smart scales. 


How can I get the most accurate smart scales readings?

Top tips for getting accurate readings

While you might not be able to guarantee that the readings are entirely accurate (we’ll cover that in more detail below) there are some steps you can take to make sure they are as consistent as possible: 

  • Weigh-in at the same time of day, and under the same conditions each time. For many, this might be first thing in the morning, before you’ve had anything to eat or drink, and after you’ve been to the toilet. 
  • Make sure the smart scales are placed on an even surface. Some smart scales can work on carpets, but the majority will work best on a hard floor. 
  • Ideally, avoid eating or drinking up to two hours before taking a measurement. 
  • Avoid skin-to-skin contact – for example, don’t rest your hands on your hips or thighs while weighing yourself. 
  • Stay still when using them. The more you move, the harder it is for an accurate reading to be taken. 

By following these steps, you’re going to get the most consistent readings possible. Over time, this will help show you trends in your weight and body composition, allowing you to make any changes to your lifestyle that you consider appropriate. 

What do smart scales and body composition scales offer?

It’s all about what they measure

Smart scales send their information to an app on your phone or tablet to help you track changes over time. Many smart scales, such as the Withings Body Comp, can also monitor your body composition, and estimate your body fat and muscle mass, among other things. 

As we explained in our guide to body composition, understanding how much body fat and muscle you have can be helpful in a variety of ways. For example, too much fat (especially visceral fat, which wraps around your internal organs) is linked to increased risk of health problems such as diabetes, stroke and heart disease. 

Using scales to monitor these metrics can help you identify potential risks, and take action before they become a problem.  

The problems with using smart scales

Body composition readings aren’t necessarily accurate

Smart scales are not perfect, and there are question marks about how accurate they actually are. They certainly aren’t as accurate as other ways of measuring your body composition, such as a DEXA (dual energy X-ray absorptiometry) scan or hydrostatic weighing. 

Every company will have their own proprietary algorithms, and studies have shown that there can be considerable differences in the measurements one set of scales provides compared with another. 

A pair of feet stepping onto a white set of smart scalesCredit: Shutterstock/Koldunov Alexey

That said, most smart scales do provide accurate weight measurements. The bigger concern is with the effectiveness of bioelectrical impedance analysis, which relies on a small electrical current being passed through your body, and the resistance in your body being measured, and used to calculate your body composition. We explain this in more detail in our guide to how smart scales work. 

To compound this, a variety of factors can influence the readings your body composition scales provide. For instance, when you last went to the bathroom, ate or drank, exercised, and even the ambient temperature, can influence the readings you get. 


Why use body composition scales at all then?

Use them for motivation and guidance

Given the questions around the accuracy of body composition metrics, this type of smart scales is best used to provide motivation and encouragement as you go on your fitness journey.

While they may not always be entirely accurate, they do tend to be consistent with themselves. So, if you start noticing a drop in body fat over a period, you can be confident that this probably reflects what’s happening in your body. 

It’s also better to look at trends, rather than individual readings, which will tend to fluctuate a little from day to day.      

Consistency is crucial

You will build up a picture over time

Ultimately, weighing in regularly and under the same conditions is the best way to get the most from your smart scales measurements.

If you don’t yet own a set, our guide on things to look for when buying smart scales can help find a set that will be suitable for you

Steven Shaw

Written by Steven Shaw he/him


Steven Shaw has been a freelance writer for a variety of outlets, most notably TechRadar. His degree in Medieval History prepared him less adequately for his career than you might expect, but the years spent working in technology focused retail were much more helpful.

Outside of work, Steven is passionate about health and fitness, and particularly enjoys high-intensity interval training, weight training, and increasingly, spending time recovering. Steven loves reading, films and a wide variety of sports. A particular highlight was watching Viv Richards and Sachin Tendulkar batting together in an exhibition match.

He wishes he could travel more. He can also tell you a lot about the Anglo-Saxons, Vikings, and Carolingians. Most of his non-work time is spent with his young children, who are the living embodiment of high-intensity training.