Xiaomi’s smart scales (Mi Smart Scale 2, Xiaomi Body Composition Scale 2, and others) have long since ceased to be just a weight measurement device. They analyze 13 key body measures, including fat percentage, muscle mass, and water level. But many users face the problem: the numbers on the screen seem inaccurate or very different from previous measurements. Why this happens and how to get the most reliable data on fat percentage – we will examine in this guide.
It's important to understand that Xiaomi scales use bioimpedance analysis (BIA) — a weak electric current passes through the body and calculates the composition of tissues by resistance. The result is affected not only by the quality of the scales themselves, but also by your condition at the time of measurement. Even the time of day or a recent meal can distort the figures by 2 to 5%. In this article, we will not only show how to technically conduct the measurement, but also reveal the hidden nuances that are not mentioned in the official instructions.
What Xiaomi scales support fat percentage measurement
Not all Xiaomi smart scales are capable of analyzing body composition, and here is the current list of devices with feature support (data for 2026):
- 🔹 Xiaomi Mi Smart Scale 2 – basic model with analysis of 13 parameters, including fat and muscle mass.
- 🔹 Xiaomi Body Composition Scale 2 – improved version with more accurate sensor and support for Bluetooth 5.0.
- 🔹 Xiaomi Smart Scale 3 – budget option, but with a stripped-down set of metrics (fat measures, but without detailing by body segments).
- 🔹 Xiaomi Mi Body Composition Scale (first generation) – outdated model, accuracy is lower by 3-7% compared to new versions.
To check if your model supports fat analysis, look at the box or in the Mi Fit/Zepp Life app (Devices → Features section). If the list of parameters does not include Body Fat %, your scales are not suitable for this task.
Preparing for Measurement: Why It’s More Important Than It Seems
70% of the errors in measuring Xiaomi's fat percentage are due to improper preparation, and even if you follow the weighing technique and ignore these rules, the measurements can vary by 10 to 15% from the real ones.
Eliminate alcohol and caffeine|Do not engage in intensive training|Drink at least 1.5 liters of water|Eat 3-4 hours before measurement|Go to the toilet before the procedure-->
Pay special attention to the time of day. The optimal time to measure is 7:00-9:00 a.m., immediately after waking up and going to the toilet, during which time the body is in the most stable state: hydration levels are normalized, and food has not yet had time to affect metabolism. Evening measurements (after 18:00) can overstate the percentage of fat by 2-4% due to accumulated fluid and muscle fatigue.
⚠️ Warning: If you are taking diuretics or supplements (such as L-carnitine), drop them 48 hours before your measurement, which distorts your hydration levels, leading to 5-8 fat inflated levels%.
Step-by-step: how to measure the percentage of fat
When you're done, you can start measuring it. Follow this algorithm to minimize the error.
- Turn on the scales - press the platform or wait for automatic on (depending on the model).
- Launch the app – open Mi Fit or Zepp Life on your smartphone and make sure the scales are connected via Bluetooth.
- Stand on the scale with bare feet - place your feet on metal electrodes (usually marked with stripes).
- Wait for the signal, the scales will sound and start analyzing. Don't move or talk at this point.
- Check the results, and in 5-10 seconds, the scale screen and the app will show the data, and the percentage of fat will be labeled as Body Fat or Fat %.
If the scales do not show the percentage of fat, check:
- 🔋 Battery level (at a charge below 20%, some functions are turned off).
- 📱 Application version (update Mi) Fit/Zepp Life in Google Play or App Store).
- 👣 Proper foot positioning (electrodes should touch the skin, not socks).
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If the scales show a Lo error, try standing on them after a shower - wet skin conducts current better. But not wet!
Transcript of Results: What Your Fat Percentage Means
Once you get that number, it's important to interpret it correctly: Fat percentages depend on sex, age, and physical activity level, and the table below is indicative of the adult figure (America Council on Exercise):
| Category | Men (%) | Women (%) | Description |
|---|---|---|---|
| Dangerously low. | <5 | <13 | Risk of hormonal disruptions and immune problems |
| Athletes | 6–13 | 14–20 | Typical for bodybuilders or marathoners |
| Good form. | 14–17 | 21–24 | Optimal balance of health and appearance |
| Medium level | 18–24 | 25–31 | Typical of most people without regular exercise |
| Elevated | >25 | >32 | Risk of cardiovascular disease |
Important: Xiaomi scales can overestimate the percentage of fat in people with high muscle mass (such as bodybuilders) and underestimate those who suffer from swelling or fluid retention. If your performance is out of order but you feel good, do a checklist measurement in 3-5 days in the same conditions.
Why do the scales show different numbers in the morning and evening?
Common Mistakes and How to Avoid Them
Even experienced users make mistakes that distort the results, and here are the most common ones:
⚠️ Note: If you have recently got a tattoo on your leg or foot, the scales may show an Err error. Metallic pigments of the tattoo block the electrical signal.In this case, measure the fat on the other leg or use alternative methods (for example, calipers).
- 🧦 Socks or tights -- fabric creates a barrier to current. Always weigh with your bare feet.
- 💦 Wet or sweaty feet - excess moisture distorts resistance. Wash your feet with a dry towel.
- 📱 No connection to the app - without synchronizing the scales will only show weight, not body composition.
- 🏋️ Measurement after exercise – within 6-8 hours after exercise, the muscles retain water, which lowers the percentage of fat.
Another common problem is unstable readings (for example, today 22%, tomorrow 25%).
- 🔋 Replace batteries with new ones, even if the indicator shows charge).
- 🌡️ Sudden temperature changes in the room (optimally - 20-25)°C).
- 🍽️ Eating salty food the day before (detains water).
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For maximum accuracy, take measurements for a week at the same time every day, then take the arithmetic mean, which will smooth out random errors.
How to improve the accuracy of measurements: secrets of experienced users
If you need the most accurate data (for example, for diet or sports purposes), use these tips:
- Calibration of scales – once a month, reset the settings through the application: Device Profile → Data Reset.
- Use the same surface, and carpet or tile can affect stability, ideally, flat flooring without coating.
- Compare it to other methods, check your fat percentage at least once with a caliper or at a fitness club (DEXA method), which will help you understand the "mistake" of your scales.
- Update your firmware – newer versions of Xiaomi’s weights software improve analysis algorithms. Check the updates in Mi Fit every 2-3 months.
For athletes, if you build muscle, the scales can show false fat gain, which is because the BIA method doesn't distinguish new muscle tissue from fat tissue, so look at other metrics.
- 📉 Visceral Fat (visceral fat) – should be reduced.
- 💪 Muscle Mass (muscle mass) – should grow.
- 💧 Water % (water level) – a stable indicator indicates the correct balance.
Alternative ways to measure fat percentage
Xiaomi scales are convenient but not perfect.If you want higher accuracy (for medical purposes or professional sports, for example), consider alternative methods:
| Method | precision | Cost | Pluses | Cons |
|---|---|---|---|---|
| Kaliper | ±3–5% | 500–2000 ₽ | Simplicity, accessibility | Depends on the skill of the operator |
| DEXA | ±1–2% | 3000–8000 ₽ | The most accurate analysis by segment | Expensive, requires a clinic. |
| Hydrostatic weighing | ±2–3% | 2000–5000 ₽ | High precision | Inconvenient, few places available |
| 3D-Scanners (e.g. Naked Labs) | ±3–4% | 50 000+ ₽ | Visualization of change | Very expensive. |
If you choose between Xiaomi weights and alternative methods, focus on your goals:
- 🏠 For home use and general control – Xiaomi scales are optimal in terms of price / quality ratio.
- 🏋️ For sports purposes (bodybuilding, powerlifting) – combine scales with a caliper or DEXA 3 months.
- ⚕️ For medical reasons (for example, the diagnosis of obesity) - only DEXA hydrostatic.