RunStar 8E SmartScan Pro review: The most advanced body fat scale we have ever tested

A smart scale is a digital bathroom scale that not only measures body weight, but also provides key body composition metrics, such as body fat percentage, muscle mass and body water. Some of the more advanced models can also distinguish between different types of body fat, calculate your BMR (Basal Metabolic Rate, the minimum amount of calories your body needs to stay alive and function properly), or assess the ‘body age’ (biological age, an estimate of how old a person’s body is based on their various body composition stats). The best smart scales on the market can even measure heart rate and offer personalized fitness advice.

The RunStar 8E SmartScan Pro Body Fat Scale goes an even further step — it is one of the few commercially available models that can provide a segmental body analysis, meaning it can measure the differences in body fat and muscle mass between different ‘segments’ of the body. In this case, between the left arm, right arm, left leg, right leg and the trunk. That is because the RunStar 8E SmartScan Pro utilizes foot-to-hand technology (it collects the measurements from both a stand-on platform and a handle), and, according to a 2022 review published in the European Journal of Applied Physiology, this approach tends to produce more accurate results than a stand-on platform alone.

It is the first smart scale of this kind that we have tested at home, so we were excited to see whether the RunStar 8E SmartScan Pro can indeed outperform the more basic models the Live Science team reviewed in the past.

RunStar 8E SmartScan Pro Body Fat Scale review

RunStar 8E SmartScan Pro: How it works

Like most smart scales, the RunStar 8E SmartScan Pro measures body composition using Bioelectrical Impedance Analysis (BIA), or bioimpedance. It is a non-invasive method deemed safe for most people, except for individuals with implanted electronic devices (such as pacemakers) or those who are pregnant. So, how does it work?

When you stand on the platform with your bare feet and hold onto the handle with your bare hands, the RunStar 8E SmartScan Pro sends low-voltage electricity through your body. Then, it measures your body’s resistance to it. Muscles and other tissues with high water content will allow this electric current to flow freely, but tissues with low water content, such as your body fat, will not let it pass through with the same ease. The smart scale then converts these electrical data points into body composition metrics and sends the results to the Starfit app.

Mind you, smart scales, even those as complex as the RunStar 8E SmartScan Pro, should not be treated as diagnostic tools. Bioimpedance is not as precise as Dual Energy X-ray Absorptiometry (DEXA) and other clinically validated methods of measuring body composition. Moreover, plenty of factors can affect BIA readings (hydration level and skin temperature, for example). Smart scales are therefore best used as tools for casual check-ins and identifying long-term trends.

RunStar 8E SmartScan Pro: Design

• Suitable for taller individuals
• Sturdy stand-on platform, but a fragile handle
• Does not tend to smudge

The RunStar 8E SmartScan Pro costs around $144.55 — about two to three times more than most stand-on smart scales on the market. We think it is worth the money, though. It is a well-made piece of kit that gets the basics right, and that is not something we can confidently say about the majority of smart scales we have used before.

To start with, the RunStar 8E SmartScan Pro is refreshingly inclusive. It has a comfortably large stand-on platform with a broad measurement area — approximately 13 by 13 inches. To put it into perspective, most smart scales have a platform measuring 11.8 by 11.8 or 12.6 by 12.6. As a result, it can be comfortably used by people with larger feet or a wider stance. We also liked that the RunStar 8E SmartScan Pro caters to taller individuals. The extendable cable that connects the handle to the platform is quite long, and even with our 6’1 height, we could take the measurements without having to stoop over.

The RunStar 8E SmartScan Pro is quite well-made, too. The stand-on platform is made of tempered glass that feels sturdy and resilient, and there is anti-slip padding at the back that keeps the scale in place during measurements. All that, and yet this smart scale weighs only 6.6 pounds (3kg), making it easy to move around the house. We also liked that the glass surface on the platform did not tend to smudge. Having to constantly wipe and polish the bathroom scales is perhaps our biggest pet peeve when it comes to these devices, so we are pleased to say that it is indeed not the case with the RunStar 8E SmartScan Pro.

There is one major downside, though — the plastic handle. We thought it was quite fragile and flimsy. The cable did not feel too durable, either, plus it jammed on us on several separate occasions. In all fairness, fiddling with the cable would usually bring it back to normal, but we would still prefer something less exposed to accidental damage.

RunStar 8E SmartScan Pro: Features

• Over 21 body composition metrics
• Segmental body analysis for fat and muscle distribution
• Printable reports that can be shared with others

Setting up the RunStar 8E SmartScan Pro was easy — it quickly connected to the Starfit app, where we set up our account by answering several questions about our age, height and fitness goals, and were also instructed on how to use the device. Using this smart scale was also relatively straightforward. Each full weigh-in took approximately 10 seconds, and the app alerted us every time we needed to adjust our position and redo the measurement.

Right after weigh-ins, a small, colorful LCD screen located on the handle would display seven of our key metrics, including BMI, body fat and muscle mass, as well as a quick comparison to previous results. If these comparisons reflected our fitness goals (for example, we lost body fat when we set our goal to weight loss), we would get a short celebratory message (‘well done!’); if they did not (such as when we gained body fat), we would get a motivational comment (‘cheer up!’). Personally, we did not mind that — in fact, we thought these messages were a nice touch. However, some people may find that commentary slightly intrusive.

Additional body composition metrics and segmental body analysis can then be accessed in the Starfit app. This is also where users can review their body composition data by day, week, month, or year — the app tracks changes in the body weight, fat-free body weight, BMI, body fat percentage, fat mass, subcutaneous (under skin) fat percentage, visceral (around organs) fat percentage, body water percentage, muscle mass, skeletal muscle percentage, bone mass, BMR, protein percentage and body age. Each of these metrics came with a short explanation of what is measured and a scale showing where your results fall within the guidelines (for example, ‘low’, ‘standard’ or ‘excellent’ for muscle mass).

We had mixed feelings about these descriptions. While they are relatively well-explained and factually correct, they seem to lack the detail and necessary context that would benefit exercise novices and those who have never used a smart scale before. As such, the RunStar 8E SmartScan Pro may not be the best option for complete beginners, as they may find it overly complex or even slightly intimidating.

We were also slightly disappointed that the Starfit app does not store any historical data related to segmental fat and muscle analysis, and it only displays results collected during the last weigh-in. This can be a major issue for athletes, bodybuilders and anyone who wants to monitor changes within a specific body segment.

On the other hand, the RunStar 8E SmartScan Pro allows you to generate detailed body composition reports. They can be either printed or shared online — with fitness coaches and healthcare professionals, for example. You could technically track changes in segmental fat and muscle composition by downloading and storing them on your mobile device.

RunStar 8E SmartScan Pro: Accuracy & performance

• Good weighing accuracy
• Relatively accurate body composition analysis
• Up to three months of battery life

Performance is one of the best aspects of the RunStar 8E SmartScan Pro. First, it has a long battery life. According to the brand, this USB-C smart scale can last up to 2,160 hours (three months) on a single charge — and it appears true. We have barely used any battery life on our testing unit over a month-long testing period, despite multiple weigh-ins and changes in our preferred settings.

Connectivity-wise, the RunStar 8E SmartScan Pro also delivers. We have not experienced any problems connecting our smart scale to the Smartfit app or third-party platforms, and the measurements were always provided on time and without data transfer interruptions. It is a strong point for us — we have battled enough smart devices with connectivity issues to know how this performance aspect can make or break the overall user experience.

Last, but not least, the tracking accuracy. We compared the body composition measurements taken with the RunStar 8E SmartScan Pro to the data we obtained with a FitQuest machine — a much bigger, more precise bioimpedance scale used in our local gym — and were quite impressed with the results. For example, the difference in body weight readings was only 0.22 lbs (0.1 kg). In that regard, this smart scale is as accurate as the premium Garmin Index S2.

When it came to body composition analysis, the RunStar 8E SmartScan Pro slightly overestimated our body fat and muscle percentage (by 4% and 2%, respectively), and underestimated our body water by 3%. However, it still proved to be more accurate than the Renpho Smart Scale, a model we named as the best model overall in our guide to the best smart scales. The Renpho smart scale overestimated our tester’s body fat percentage by 9%, and underestimated their body water reading by 5%.

As the FitQuest does not offer segmental body composition analysis, we could not assess how effective the SmartScan Pro was at differentiating between different body parts. However, its measurements seemed largely accurate to us.

RunStar 8E SmartScan Pro: User reviews

At the time of writing this review, Amazon‘s customer reviews rated the RunStar 8E SmartScan Pro at 4.3 out of 5 stars. Nearly three-quarters of buyers gave it the highest score, generally praising this smart scale for its advanced body composition measurements, speedy connectivity with major fitness apps and printable progress reports.

As one happy user commented, “I recently upgraded my health-tracking tools with this Runstar Smart Scale, and I seriously can’t believe how helpful it’s become. Beyond the measurements, the app makes it easy to see real progress. My data is organized by day, week, month, or year, and I love being able to generate shareable or printable reports. All in all, this scale doesn’t just show numbers—it helps me own my journey. Highly recommended!”

That said, the RunStar 8E SmartScan Pro received mixed opinions on its design and accuracy. Negative remarks, on the other hand, tended to revolve around individual faulty units, and several users criticized some of the terminology used in the Starfit app.

One user said, “The language used (terms like “obese,” “plump,” or “overweight”) is blunt, potentially misleading, and based on outdated classification models. These may trigger or validate distorted body perceptions, especially for users unfamiliar with how these values are calculated or misapplied.”

Should you buy the RunStar 8E SmartScan Pro?

✅ Buy it if: You are an exercise data geek or a fitness coach looking for a well-made, well-connected smart scale. The RunStar 8E SmartScan Pro delivers an impressive range of relatively accurate body composition stats, and it easily connects with third-party apps and devices.

❌ Do not buy it if: You are on a budget or looking for your first-ever smart scale. The RunStar 8E SmartScan Pro is a formidable bit of kit, both in price and functionality, and may feel too complex and data-driven for complete beginners.

If RunStar 8E SmartScan Pro is not for you

If the RunStar 8E SmartScan Pro is too much for your budget, we would recommend these more affordable models instead: our all-time favorite Renpho Elis 1 and the slightly more basic (but cheaper) Wyze Scale X. These stand-on smart scales are less technologically advanced, but they offer a relatively good range of body composition stats and decent tracking accuracy — and they cost less than $50.

If you are an athlete, however, you may be better off with the more premium Garmin Index S2. It costs nearly as much as the RunStar 8E SmartScan Pro, but it is well worth it if you want to prioritize precision and progress tracking tools — it is by far the most accurate and reliable stand-on smart scale we tested.

RunStar 8E SmartScan Pro: How we tested

We spent over a month testing the RunStar 8E SmartScan Pro Body Fat Scale, assessing its design, functionality, ease of use, connectivity with third-party devices and value for money. We also compared the body composition measurements taken with this smart scale to the data we obtained with a FitQuest machine (a much bigger, more precise bioimpedance scale used in our local gym), and gave our verdict on its general accuracy and reliability.