Smart scales are designed to measure not only weight but also body fat percentage. They use a technology called bioelectrical impedance analysis (BIA) to estimate the amount of fat in the body. This method works on the principle that fat conducts electricity less effectively than other tissues, such as muscle and water.
When you step on a smart scale, it sends a small electric current through your body. This current flows easily through the water and muscle in your body, but encounters more resistance when it encounters fat. The scale measures the resistance encountered by the electric current and uses that information to estimate your body fat percentage.
The process is quite quick and painless, with the electric current being very low and not noticeable to the person using the scale. However, it's important to note that the accuracy of the measurements can vary. Factors such as hydration levels, temperature, and even the positioning of your feet on the scale can influence the readings.
To improve the accuracy, many smart scales utilize advanced algorithms and factors like age, height, and gender to provide a more accurate estimation of body fat percentage. Some scales also incorporate additional sensors, such as pulse wave velocity (PWV) sensors or sensors that measure heart rate, to further enhance the accuracy of the readings.
Overall, smart scales offer a convenient and non-invasive way to keep track of your body fat percentage. While they may not provide medical-grade accuracy, they can still be a valuable tool in monitoring your body composition and overall health.
Best Smart Scales of 2025
1
Rating is 5 out of 5
eufy Smart Digital Bathroom Scale P2 Pro with Wi-Fi Bluetooth, 16 Measurements Including Weight, Heart Rate, Body Fat, BMI, Muscle & Bone Mass, 3D Virtual Body Mode, 50 g/0.1 lb High Accuracy
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FULL BODY COMPOSITION ANALYSIS: Track your daily progress and monitor 16 detailed measurements of your body including weight, body fat, BMI, muscle mass, bone mass, and even your standing heart rate.
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ADVANCED TECHNOLOGY FOR HIGH ACCURACY: The sensitive ITO-coating technology on Smart Scale P2 Pro allows you to step on anywhere for the bioelectrical impedance analysis (BIA) to still give insightful readings. High-precision manganese steel sensors can detect subtle weight changes accurately up to 50 g (0.1 lbs) so you can celebrate even the little wins.
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3D VIRTUAL MODEL: Watch your body's progress throughout your fitness journey with a virtual, U-Body 3D model, featuring you. Your avatar will match the proportions and measurements of your biceps, chest, waist, hips and thighs that you input, and give you a detailed visual of your changes.
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THIRD-PARTY APP SYNCING: Connect to the EufyLife App using Wi-Fi or Bluetooth and automatically upload data. You can also sync EufyLife with Apple Health, Google Fit, or Fitbit to keep your progress all in one place.
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FOR THE WHOLE FAMILY: Add unlimited users to the app and track everyone's personal fitness journey. With Baby mode or Pet mode, you can monitor the healthy, everyday growth of your baby or pet.
2
Rating is 4.9 out of 5
iHealth Nexus Smart Scale for Body Weight Bluetooth, Digital Bathroom Scale Body Fat and Muscle, Body Composition Monitor Health Analyzer for BMI Compatible for iOS & Android Accurate to 0.1lb-White
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Full Body Composition - iHealth Nexus scale for body weight displays 9 body compositions to better understand yourself. Monitors weight (kg, lb, st), body fat, body water, muscle mass, lean mass, and bone mass. Calculates BMI, daily caloric intake, and visceral fat.
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Accuracy You Can Trust - iHealth smart scale features two pairs of super-sensitive g-shaped sensors and its own developed algorithm to ensure more precise measurements compared to other body fat scales. The measurement results are accurate to 0.2lb/0.1kg. Maximum load capacity reaches 400 lbs.
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Highly Compatible – The iHealth MyVitals app syncs with Apple Health, Google Fit, and Fitbit to share data with your preferred health tracker.
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Multi-user Friendly - This digital scale lets you share a scale with your family. Automatically identify up to 8 users and access their personal weight history. The scale for body weight automatically recognizes who's who after syncing with your smartphone.
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Sturdy Construction - Our weight scale features 6mm premium tempered glass and a full bottom cover, which provides increased strength and support. The rounded corners and anti-skid padding provide extra protection against slipping and collisions.
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Rating is 4.8 out of 5
Smart Scale for Body Weight and Fat Percentage, RunSTAR High Accuracy Digital Bathroom Scale with Large Display for BMI Heart Rate FSA&HSA Eligible 15 Body Composition Analyzer Sync with Fitness App
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All in One Display: Unlike normal smart body fat scales, the RunSTAR scale with an extra large VA display screen enables you to get 5 key body metrics even without your phone. The screen shows weight, body fat rate, BMI, heart rate and body type at the same time within 15 seconds. You can completely free your hands to know your basic health condition at a glance
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Accurate to 0.1lb: This ultra-precision body fat scale features 4 high sensitive electrodes and 4 high precision G-shape sensors that have passed 100,000 times sensor performance tests to enhance accuracy. The scale ensures measurement results accurate to 0.1lb/0.05kg and has a maximum weight capacity of 400lb/180kg
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15 Essential Body Composition Data: Fitness and health involve more than just weight. The RunSTAR Scale for body weight and fat measures 15 body composition metrics, including Weight, BMI, Body Fat, Muscle Mass, Heart Rate and more, which enables you to know more about yourself and helps you personalize your fitness and health plan.
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Multifunctional APP: You can download Starfit app from App Store or Google Play to monitor and track your body data over time periods anytime anywhere. The app also syncs easily with other fitness apps like Apple Health, Google Fit, and Fitbit. Moreover, the smart scale supports offline measurement, which allows the data be measured and automatically synced onto the APP after the first measurement
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Share with Friends and Family: With the ability to create up to 24 user profiles and identify the user automatically and instantly when one steps on, the RunSTAR Scale is perfect to share with your family and friends. Moreover, the app features different modes to meet different needs. For example, you can use Baby Mode to help track baby or pet’s growth. The scale is great for bodybuilders, weight loss enthusiasts, and anyone who wants to maintain a healthy lifestyle.
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Rating is 4.7 out of 5
Withings Body+ Smart Wi-Fi bathroom scale for Body Weight - Digital Scale and Smart Monitor Incl. Body Composition Scales with Body Fat and Weight loss management
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FSA & HSA Eligible.Compatible Devices : iPhone 4s (or higher), iPod Touch 4th Gen (or higher), iPad 2nd Gen (or higher), Android device running Android 5.0 (or higher). WiFi 802.11 b/g/n, compatible with WEP/WPA/WPA2-personal networks
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#1 BEST-SELLING SMART SCALE In the US. One of the smartest digital scales for body weight, making it a bathroom essential and home must haves in electronic scale.
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BODY COMPOSITION - The withings scale functions as a bmi measurement tool or body fat analyzer. This bathroom scale monitors weight, measures body fat & water %, muscle & more. It's a fitindex scale.
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HIGHLY COMPATIBLE digital bathroom scale- This digital bluetooth scale, unlike other bathroom scales, syncs with apple watch plus more than 100 top health and fitness apps incl. Apple health & more
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AUTOMATIC SYNCHRONIZATION - Data from every weigh-in appears automatically via Wi-Fi in the free health Mate app. Making it easy to keep track at home workout progress. An Amazon must haves.
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ACCURATE WEIGHING - Wi-Fi to ensures your measurement on this body weight scale is accurate & position control technology guides you to getting a precise weight measurement to 100g .
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MULTI-USER FRIENDLY - Up to 8 users can weigh themselves and access their personal weight histories, as the scale automatically recognizes who's who. Unlike other bathroom scales for weight.
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FOR EVERY STAGE OF LIFE - Keep track of the whole family’s growth with Pregnancy Tracker (healthy weight gain range and obstetrician-reviewed advice) and Baby Mode, to track the youngest members.
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LONG BATTERY LIFE - Body+ digital weight scale and body fat scale operates up to 18 months using four standard AAA batteries (incl.). The battery of this body fat measurement device is rechargeable.
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"""ALEXA, ASK WITHINGS"" - Now your voice can help you manage your weight on this digital bathroom scale with an Alexa Skill that works with Health Mate. IN THE BOX - Body+ White, Carpet feet, Alkaline cells already installed, Quick installation guide (English, French, German, Italian, Spanish)"
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Rating is 4.6 out of 5
Etekcity Smart WiFi Scale for Body Weight, FSA HSA Store Approved, Compatible with Apple Health, Accurate Body Fat Muscle Mass Biometric Analysis, Digital Bathroom Measurement Device for Fitness
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FSA / HSA eligible. Syncs with apple watch
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FIRST-RATE QUALITY: Don't settle for less. As the selling brand of body weight scales in the US, Etekcity is known for innovative and high-performing products. Source: Stackline/Retail Intelligence, U.S. Amazon Data Market Share, February 2019-2021
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FULL BIOMETRIC ANALYSIS: Getting thinner but not losing any weight. This is due to muscle gain and fat loss. A conventional scale won't show you that, but The Apex scale will. View 14 biometric measurements, including heart rate, with Etekcity Apex scale
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FUN, INTERACTIVE DISPLAY: Unlike conventional scales, this display allows you to track progress and provides fun, interactive messages even without having to get your phone. The measurements will automatically sync to the VeSync app via wifi connection
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JUST ASK ALEXA: "Alexa, ask VeSync how much weight I have lost this month." Keep the motivation going with hands-free voice control
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IMMERSIVE APP EXPERIENCE: Set goals and track your progress with data graphs, sync information with Apple Health, Google Fit, FitBit, MyFitnessPal, and Samsung Health. Rest assured, VeSync will not share your personal information with any third parties
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CONSISTENT ACCURACY: Upgraded with ITO-coating for accurate results, the Apex scale guides your feet to the right place, so you don't have to guess anymore
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ONE SCALE FOR THE WHOLE FAMILY: Use Zero-Current Mode to safely measure weight and BMI during pregnancy, while Baby Mode helps track baby or pet's growth. With unlimited user profiles for family and friends, this scale is designed with everyone in mind
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THOUGHTFULLY DESIGNED: No batteries needed Used an average of 3x per day, the scale can last up to 6 months on a single charge. Additionally, the scale's arched structure provides long-lasting durability and core stability
6
Rating is 4.5 out of 5
GE Smart Scale for Body Weight and Fat Percentage with All-in-one LCD Display, Digital Bathroom Weight Scales Bluetooth Rechargeable Body Fat Scale, Accurate Weighing Scale, 396 lbs
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Full Body Analysis: The GE Fit Plus Smart Body Fat Scale accurately analyzes and tracks nine key fitness metrics. These include body weight, body fat percentage, muscle mass, body water, visceral fat, fat-free body weight, BMI, BMR, and bone mass directly to your phone via Bluetooth. This scale will help you reach your fitness goals even faster!
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Large Vertical Alignment LCD Display: This model features a large color LCD screen that displays your weight and five other major body composition readings directly on the scale, in addition to app displays on your phone. The large and easy to read, Vertical Alignment (VA) LCD panel provides the best contrast and colors to perfectly present your body composition metrics
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Reliable and Accurate Measurements: This scale is equipped with E-shaped sensors with sensitive electrodes that accurately provide your weight metrics down to 0.2 lb. increment. This scale's capacity is 396lbs. GE quality standards ensure the reliability and consistency of our smart scales
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Simple & Convenient: No worry about batteries because this scale doesn’t need them. You can easily charge it the same way you charge your cell phone. Featuring step-on technology, auto-calibration, and auto user-recognition for up to 8 users, this scale only requires you to step on it. Once the scale reads your measurements, it will send the results directly to your phone via Bluetooth. This scale doesn't require an extra step to calibrate, and you don't need to carry your phone while you weigh
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User-Friendly App: The free app "Fit Profile"(Authoried by GE) is simple to use and supports an unlimited number of users, and keeps track of your progress graphically to help you and your family stay healthy. Whether you are on the go, or just wanting to know, you can open your app to check your measurements in detail anywhere and anytime. Also, it can sync with Fitbit, Google Fit and Apple Health. Please be assured Fit Profile, will never share your personal informaiton with any third parties
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Practical Design: GE smart scale features troubleshooting displayed on the scale screen to help you better use it and get accurate measurements. For example, "Err2" means that you stand on it for too long. After the weight number flashes twice, the weighing is over (see more details in the user manual)
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Precautions: Do NOT use if you have a Pacemaker or any other internal medical device in your body. The scale could be low battery due to long-time storage, please charge it when receiving.
7
Rating is 4.4 out of 5
RENPHO Smart Scale for Body Weight, Digital Bathroom Scale BMI Weighing Bluetooth Body Fat Scale, Body Composition Monitor Health Analyzer with Smartphone App, 400 lbs - Black Elis 1
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Renpho Health app works in connection with fitness apps. Easy setup app works with Fitbit App, Google Fit. Renpho already has millions of happy global users.
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13 essential body measurements. Body weight shows on the scale, other body composition data including weight, BMI, body fat percentage stored in the app. Track everybody's metrics change on Renpho Health app.
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User-friendly app. Download Renpho Health app at App Store or Google Play, also works with Apple Watch (Except for Apple Watch Series 1). Renpho Health app works with Bluetooth 4.0 and above.
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High-Quality Innovation. Auto calibration, high precision sensors measure in increments of 0.2 lb, 0.05 kg with 400lbs, 180kg capacity. 4 high sensitive electrodes. DO NOT let the sides of the scale, especially the four corners of the surface tempered glass hit any object, and it is recommended to wrap the four corners of the glass with soft objects.
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Monitor your progress, unlimited users and baby weighing mode. Renpho connects with apps to help motivate toward your goals, save historical data, and track your daily, weekly, and monthly progress. Use baby weighing mode for weighing baby or pets, 1 scale for whole family, support for adding unlimited users.
8
Rating is 4.3 out of 5
Etekcity Smart Scale Digital Weight and Body Fat, Bathroom Scales Accurate for People's Bmi Muscle, Bluetooth Electronic Body Composition Monitor Syncs with App, 400lb
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Unparalleled App Experience: Elevate your fitness journey with us. Our scale stands out with the free vesync app, offering a customized diet and exercise plans based on your life habits. Achieve your fitness goals scientifically with ease (FSA/HSA eligible)
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Unmatched Precision: Benefit from our 10 years of professional experience and join over 5 million satisfied customers across 30 countries, our scale boasts high-precision sensors for accuracy in increments as small as 0.05 lb
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Versatile Weighing Solution: Our scale offers 3 different modes designed to cater to all your needs. Zero-Current Mode ensures a safe weigh-in option, Baby Mode tracks baby or pet growth, and For Light Items weighs items as light as 100g
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Use with Ease: Seamlessly integrate our scale into your fitness routine. Compatible with APPLE WATCH and syncs data with popular fitness apps like Apple Health, Samsung Health, Google Fit, FitBit, and MyFitnessPal. Supports unlimited users for convenience
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Weigh Smarter: Beyond analyzing 13 biometrics, setting goals, and viewing progress graphs, our scale offers even more intelligence. Connect the app to Alexa for hands-free voice control and quick answers. Rest assured, VeSync prioritizes your privacy
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Extra-Large Display: Enjoy an impressive visibility and readability with our extra-bright LED display featuring large and clear numbers. Bigger is better
Are smart scales accurate in measuring body fat?
Smart scales can provide an estimation of body fat by using a method called bioelectrical impedance analysis (BIA). BIA works by sending a small electrical current through the body and measuring the resistance encountered. Since fat tissue conducts electricity differently than muscle or bone, the scale can estimate body fat based on the resistance measurement.
However, it is important to note that smart scales' accuracy in measuring body fat can vary. Factors such as hydration levels, conductive ability of skin, and individual differences can affect the accuracy of the readings. Additionally, the algorithms used by smart scales to calculate body fat can also vary across different brands and models, leading to inconsistent results.
While smart scales can give you a general idea of your body fat percentage, they may not be as accurate as methods like dual-energy X-ray absorptiometry (DXA) scans or professional body composition testing. For precise and reliable measurements of body fat, it is recommended to consult with a healthcare professional or use more advanced body composition measurement methods.
Can smart scales measure body fat for all body types?
Smart scales can generally measure body fat for a wide range of body types. However, there may be limitations in accuracy for certain individuals, especially those with unique body compositions or extreme weight fluctuations.
Smart scales use a method called bioelectrical impedance analysis (BIA) to estimate body fat percentage. This technique sends a small electrical current through the body and measures how it flows through different tissues, including fat and muscle. The scale then uses algorithms to calculate body fat percentage based on this information.
While BIA can provide a rough estimate, it is not as accurate as more advanced methods such as dual-energy X-ray absorptiometry (DXA) or hydrostatic weighing. BIA can be affected by factors like hydration levels, body temperature, and electrical resistance, which may vary between individuals and affect the accuracy of measurements.
Additionally, people with a high proportion of muscle mass, such as athletes or bodybuilders, may receive inaccurate readings from smart scales as these devices may tend to overestimate body fat percentage in highly muscular individuals.
Therefore, while smart scales can provide a convenient and relatively affordable means of measuring body fat for many people, it is important to interpret the results with caution and consider them as estimates rather than absolute values. For more precise measurements, it may be advisable to consult a healthcare professional or use more advanced techniques.
How do smart scales calculate body fat percentage?
Smart scales typically use a technology called bioelectrical impedance analysis (BIA) to calculate body fat percentage. Here's how it works:
- Electrical current: The scale sends a small, safe electrical current through the body. To do this, the person stands barefoot on the scale's metal electrodes or holds the scale's handles.
- Resistance measurement: The electrical current encounters varying resistance as it passes through different tissues in the body. Fat tissue has high resistance, while muscle tissue has lower resistance.
- Impedance measurement: The scale measures the impedance, which is the combination of resistance and reactance (the delay caused by the capacitance of cell membranes), to calculate the total impedance.
- Estimation algorithms: The smart scale then uses built-in algorithms to estimate the body fat percentage based on the recorded impedance. These algorithms use mathematical formulas that take into account gender, age, height, weight, and sometimes additional data like waist circumference to provide an estimation of body fat percentage.
It's important to note that while smart scales can provide an estimate of body fat percentage, the accuracy may vary, and they may not be as precise as more sophisticated methods like dual-energy x-ray absorptiometry (DXA) or hydrostatic weighing. However, smart scales can still be useful as long as you understand that the measurements are approximate and can be influenced by factors such as hydration level, muscle mass, and other individual characteristics.
How do smart scales ensure data privacy and security?
Smart scales ensure data privacy and security through various measures:
- Data encryption: Smart scales use encryption techniques to protect the data that is transmitted between the scale and other devices like smartphones or cloud servers. This ensures that the data cannot be intercepted or accessed by unauthorized individuals.
- User authentication: Smart scales often require users to create accounts and authenticate themselves before accessing their data. This helps to ensure that only authorized users have access to their own recorded measurements.
- Secure cloud storage: Many smart scales store the collected data in the cloud. To ensure data privacy, reputable smart scale providers use secure cloud storage with robust security measures, such as data encryption, access controls, and regular security audits.
- Privacy settings: Users can typically set privacy preferences and control what data is shared with others. This enables users to decide who has access to their measurements and whether they want to share their data with any external applications or services.
- Anonymization and aggregation: To further protect user privacy, smart scales may aggregate and anonymize data before sharing it for research or analysis purposes. This ensures that individual users cannot be identified from the shared data.
- Compliance with regulations: Smart scale manufacturers adhere to data protection laws and regulations, such as the General Data Protection Regulation (GDPR) in the European Union. Compliance ensures that user data is handled securely and transparently.
- Regular software updates: Manufacturers of smart scales often release software updates to address any security vulnerabilities and ensure the devices remain secure over time. Users should regularly update their smart scale's firmware to benefit from the latest security enhancements.
However, it is still crucial for users to choose reputable and trusted smart scale brands and review their privacy policies before using a smart scale to ensure their privacy and security requirements are met.
