Xiaomi Body Composition Scale S400 Pro: More Than Just a Weight Reading

For many people, tracking health and fitness starts with one simple number: body weight.

But weight alone does not tell the full story.

Two people can weigh exactly the same while having very different proportions of body fat, muscle mass and body water. That is where modern body-composition technology can provide additional context.

The Xiaomi Body Composition Scale S400 Pro takes everyday weighing a step further by combining weight measurement with a range of body-composition metrics, giving users a more detailed picture of their changing body over time.

Available through Health-Tech, the S400 Pro is designed for people who want more information than a traditional bathroom scale can provide.

What Is the Xiaomi S400 Pro?

The Xiaomi Body Composition Scale S400 Pro is a smart body-composition scale featuring a built-in 3.5-inch TFT colour display, a large 300 × 300 mm weighing surface and Bluetooth connectivity to the Xiaomi Home app.

Rather than displaying only body weight, the S400 Pro can provide information across 25 body-composition indicators, including:

• Weight

• BMI

• Body fat percentage

• Fat mass

• Muscle mass

• Muscle percentage

• Body water

• Protein mass

• Visceral fat level

• Skeletal muscle mass

• Bone mineral content

• Basal metabolic rate

• Heart rate

• Fat-free body weight

• Body type

• Estimated waist-to-hip ratio

• Body age

• Weight, muscle and fat control indicators

The full report is available through the Xiaomi Home app.

Why Body Composition Matters

Body weight is useful, but it is only one measurement.

When someone changes their training routine, nutrition habits or general lifestyle, changes in body weight do not always tell the complete story. Tracking additional measurements can provide greater context around how the body is changing.

For example, a person's scale weight may remain relatively stable while other measurements change over time.

This is one reason body-composition tracking can be useful alongside a consistent fitness or wellness routine.

The goal is not necessarily to focus on one isolated reading. Instead, the value comes from observing trends over time.

Dual-Frequency Bioelectrical Impedance Technology

One of the key features of the S400 Pro is its use of dual-frequency bioelectrical impedance technology.

The scale uses 50 kHz and 250 kHz frequencies to assess electrical impedance and generate estimates for body-composition measurements such as body fat and body water. Xiaomi states that the technology was benchmarked against DEXA testing, with a reported correlation greater than 0.93 in the manufacturer's referenced validation study.

It is important to understand what this means in practical terms.

The S400 Pro is a consumer body-composition device, and its body-composition figures should be treated as estimates and tracking indicators rather than clinical diagnostic measurements. For most users, the most useful application is looking at trends under consistent measurement conditions rather than becoming overly focused on a single day's number.

A Large Display Designed for Everyday Tracking

Another standout feature is the built-in 3.5-inch TFT colour display.

Instead of immediately reaching for a smartphone, users can view measurement information directly on the scale. Xiaomi also allows display content and trend cards to be customised through the Xiaomi Home app.

This makes the S400 Pro feel less like a traditional bathroom scale and more like a compact personal tracking device.

The scale can also store up to 160 measurement records locally before synchronising with the Xiaomi Home app when connected.

Track Your Progress Through the Xiaomi Home App

Bluetooth connectivity allows the S400 Pro to work with the Xiaomi Home app, where users can review measurement history and monitor trends across multiple metrics.

This is particularly useful because body composition is best understood through patterns over time.

Rather than asking:

"What did the scale say today?"

a better question can be:

"What has changed over the last few weeks?"

That shift from individual readings to longer-term trends can make personal tracking more useful and informative.

Designed for the Whole Household

The S400 Pro supports up to 36 user profiles, making it possible for multiple members of a household to track their own measurements. Xiaomi states that body-composition measurements are supported for users aged 6–80, subject to the manufacturer's measurement requirements and limitations.

The scale has a measurement range of 0.1 kg to 150 kg, with support for kilograms and pounds.

It can also be used for certain non-body weighing scenarios, such as weighing smaller items, with Xiaomi specifying a separate small-item weighing range.

A Premium, Minimalist Design

The S400 Pro combines technology with a clean, modern appearance.

Its large 300 × 300 mm ITO-coated tempered-glass surface provides a broad standing area, while the dark mirrored finish and integrated display give the device a contemporary look. Xiaomi also incorporates curved glass edges and silicone feet into the design.

At Health-Tech, we like products that combine practical technology with a design that fits naturally into a modern wellness environment — and the S400 Pro fits that approach well.

Battery Life Built for Long-Term Tracking

According to Xiaomi's manufacturer testing, the S400 Pro can achieve up to 150 days of battery life under specified test conditions using four AAA alkaline batteries and three measurements per day. Actual battery life can vary depending on usage and environmental conditions.

For a device designed around long-term tracking, that means less attention needs to be spent on charging or replacing batteries.

How to Get More Meaningful Measurements

Consistency matters when tracking body-composition trends.

For the most useful comparisons, try to measure under similar conditions each time. Differences in hydration, timing, recent meals, exercise and other factors can affect body-composition readings.

The objective should therefore be to establish a repeatable tracking routine and focus on longer-term trends rather than reacting to every individual measurement.

Who Is the Xiaomi S400 Pro For?

The S400 Pro may be particularly useful for people who want to:

Track body-composition trends
Go beyond body weight and monitor additional measurements over time.

Support fitness tracking
Use body-composition information alongside training and lifestyle data.

Monitor progress more comprehensively
Compare changes in body weight, body fat, muscle-related measurements and other indicators.

Create a more data-driven wellness routine
Use technology to make personal tracking easier and more consistent.

Track the whole household
Use multiple profiles for different family members.

Why Health-Tech Includes It

At Health-Tech, we see value in combining products that support better information, better tracking and better awareness.

The Xiaomi Body Composition Scale S400 Pro is not intended to replace professional medical assessment. Instead, it provides consumers with a convenient way to collect additional information about their body and monitor trends over time.

For anyone building a more structured approach to fitness and wellness, having consistent data can be a useful part of the bigger picture.

Final Thoughts

The Xiaomi Body Composition Scale S400 Pro is much more than a conventional weighing scale.

With 25 body-composition indicators, dual-frequency bioelectrical impedance technology, a built-in colour display, Xiaomi Home app integration, Bluetooth connectivity and support for multiple user profiles, it provides a more detailed approach to everyday body tracking.

Most importantly, the real value of a device like this comes from consistency.

One measurement tells you what is happening today.

A series of measurements can help you understand what is changing over time.

For people who want to take a more informed approach to tracking their fitness and wellness journey, the Xiaomi S400 Pro offers a practical way to start collecting that information.

Explore the Xiaomi Body Composition Scale S400 Pro at Health-Tech

Health-Tech provides this article for general educational and product-information purposes. Body-composition readings from consumer devices are estimates and should not be treated as a medical diagnosis or a substitute for professional medical assessment.