Fact Check: Are smart scales accurate?

Are Smart Scales Accurate?

The claim under examination is whether smart scales provide accurate measurements of weight and body composition. As smart scales have gained popularity for their ability to track various health metrics, questions about their accuracy have become increasingly relevant. This article will explore available research and reviews to assess the reliability of smart scales in measuring weight and body composition.

What We Know

Accuracy for Weight Measurement: A study published in the Journal of Medical Internet Research assessed the metrological accuracy of several commercially available smart scales. The findings indicated that these scales were reasonably accurate for measuring body weight but not for body composition metrics such as body fat percentage and muscle mass 1.
Consumer Reviews and Testing: Various consumer review sites have tested multiple smart scales. For instance, Verywell Fit reported that out of 30 tested smart scales, only 12 met their standards for accuracy and usability. They noted that while some scales were intuitive and easy to use, discrepancies in body composition readings were common 3.
Recommendations from Experts: Publications like PCMag and Wirecutter have recommended specific smart scales based on their testing. They emphasize that while some scales provide consistent weight readings, their body composition metrics may vary significantly from professional standards 2 5.
Variability in Results: According to a recent article from TechRadar, budget-friendly smart scales tend to be reasonably accurate but may not match the precision of higher-end models. They also noted that individual factors, such as hydration levels, can influence the accuracy of body composition readings 7.
Limitations of Smart Scales: Many reviews highlight that smart scales often use bioelectrical impedance analysis (BIA) to estimate body composition, which can be affected by factors like hydration and recent physical activity. This method may lead to inaccuracies, particularly for individuals with higher muscle mass or those who are very lean 1 9.

Analysis

The evidence regarding the accuracy of smart scales presents a mixed picture. The study from the Journal of Medical Internet Research provides a scientific basis for understanding the limitations of smart scales, particularly in body composition analysis 1. However, it is important to note that this study may have limitations in terms of sample size and the specific models tested, which could affect the generalizability of its findings.

Consumer reviews from sources like Verywell Fit and PCMag offer practical insights into user experiences with smart scales. However, these reviews are often influenced by the testers' preferences and may reflect a selection bias, as they typically focus on popular models that are marketed heavily 3 5. Furthermore, many of these reviews do not disclose potential conflicts of interest, such as sponsorship or partnerships with scale manufacturers.

The variability in results across different scales and testing conditions raises questions about the reliability of smart scales for body composition tracking. While they may provide a convenient way to monitor weight, the accuracy of body fat and muscle mass readings can be questionable. The reliance on BIA technology, which has known limitations, further complicates the assessment of these devices 1 7.

Conclusion

Verdict: Partially True

The claim that smart scales provide accurate measurements is partially true. Evidence suggests that while smart scales can deliver reasonably accurate weight measurements, their reliability in assessing body composition metrics, such as body fat percentage and muscle mass, is significantly less certain. Studies and consumer reviews indicate that discrepancies in body composition readings are common, and factors like hydration and individual physiology can further complicate accuracy.

It is essential to recognize the limitations of the available evidence. The studies reviewed may have sample size constraints and may not encompass the full range of smart scale models on the market. Additionally, consumer reviews can be subjective and may not always reflect the broader user experience due to potential biases.

Readers are encouraged to critically evaluate the information presented and consider their own needs and circumstances when assessing the accuracy of smart scales. While these devices can be useful tools for tracking weight, users should remain cautious about their body composition readings and seek professional advice for more accurate assessments.

Sources

Accuracy of Smart Scales on Weight and Body Composition. Journal of Medical Internet Research. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC8122302/
The 2 Best Smart Scales of 2025 | Reviews by Wirecutter. The New York Times. Available at: https://www.nytimes.com/wirecutter/reviews/best-smart-scales/
We Tested the Best Smart Scales—These 12 Are the Most Accurate and User-Friendly. Verywell Fit. Available at: https://www.verywellfit.com/best-smart-scales-4586856
The 6 Best Smart Scales of 2023, Tested and Reviewed - SPY. Available at: https://spy.com/articles/health-wellness/fitness/best-smart-scales-98769/
The Best Smart Scales for 2025 - PCMag. Available at: https://www.pcmag.com/picks/the-best-smart-scales
The Best Smart Scales of 2023 - ACTIVE. Available at: https://www.active.com/fitness/articles/best-smart-scale
Best smart scales in 2025: body composition. Tom's Guide. Available at: https://www.tomsguide.com/us/best-smart-scales,review-3469.html
Best smart scales 2025: Top digital body composition scales - TechRadar. Available at: https://www.techradar.com/best/best-smart-scales
Best smart scales of 2025, tried and tested | CNN Underscored. Available at: https://www.cnn.com/cnn-underscored/reviews/best-smart-scale
Best smart scales 2025: Track body composition in the. Live Science. Available at: https://www.livescience.com/best-smart-scales