The Xiaomi Mi Body Composition Scale 2 is not just a weight measurement device, but a full body composition analyzer with 13 parameters (from body mass index to blood viscosity). Calibration is a key process that ensures that readings are 95% or more accurate. Without it, the scales can lie to the public. ±2-5 kg, and data on muscle mass or metabolism will become useless.
In this article, you will find official and alternative calibration methods, including hidden features of the Mi Fit app, manual adjustment through the engineering menu and solutions for cases where the scales “hang” at zero or show an Err error. We will also discuss why calibration is lost (for example, after moving or replacing batteries) and how to avoid this. If your scales suddenly start lying, do not rush to carry them to the service: in 80% of cases, the problem is solved in 10 minutes at home.
Why Xiaomi Mi Body Composition Scale 2 Requires Calibration
Unlike mechanical scales, Xiaomi’s smart models use strain gauges, sensitive elements that convert strain under weight into an electrical signal.
- 🔋 Battery discharge – at voltages below 2.8 The accuracy drops by 30-40%.
- 🌡️ Temperature swings – if the scales are standing next to the battery or on the cold floor, the sensors are deformed.
- 📦 Transportation – after moving or falling (even from a height of 30 cm) requires re-tuning.
- ⚡ Electromagnetic interference – near a router, microwave or speakers.
In addition, Mi Body Composition Scale 2 analyzes bioimpedance (electrical resistance of the body), and its readings depend on the moisture of the skin, the time of day and even the phase of the menstrual cycle. ** Calibration is necessary not only for weight, but also for the correct calculation:
- 💪 Percentage of muscle mass
- 💧 Hydration level
- 🦴 Bone density
- ⚡ The speed of the basic metabolism (BMR)
Xiaomi’s official guidelines require calibration of the scales every 3-6 months, and after:
- 🔄 Replacement of batteries (even if they are of the same brand).
- 📱 Updates to the firmware through Mi Fit.
- 🏠 Transfer to a new place (for example, from carpet to tile).
Preparation for calibration: 5 mandatory steps
Before setting up, make sure that all conditions are met for accurate calibration. Ignoring at least one item can lead to Err 5 error or incorrect readings after the procedure.
Set the scales on a flat solid surface (tile, laminate, wood)
Check the battery charge (voltage) ≥ 3.0 In)
Remove from the sole of the feet cream, sweat or calluses
Connect the scales to Mi Fit via Bluetooth
Reset previous data in the application (optional)-->
1. Surface: The scales must stand on a completely flat surface, and this can be verified by means of a level (permissible slope is not more than 2).°). It is forbidden to calibrate:
- 🧵 Carpets with long pile (even thin ones).
- 🪨 Uneven tile or mosaic.
- 🛏️ Soft coatings (linoleum with substrate, cork).
2. Batteries: Use only alkaline batteries (e.g. Duracell or Energizer) Salt or rechargeable (Ni-MH) that give unstable voltage.
- Then, put the weights on them.
- If Lo flashes on the screen, replace the batteries immediately.
- For accurate check use the multimeter: voltage should be 1.5-1.6 V on each battery.
3. Indoor conditions: Optimal temperature for calibration is 20–25°C, humidity 40-60:
- 🔥 Direct sunlight (heating of the body distorts the readings).
- 💨 A running air conditioner or a working air conditioner near.
4. Body condition. For accurate bioimpedance analysis:
- 🚿 Do not wash your feet 2 hours before calibration (moisture distorts resistance).
- ☕ Don’t drink coffee or alcohol in 4 hours.
- 🏋️ Don’t play sports in 12 hours.
5.Mi Fit App Update Mi Fit to the latest version (at 2026 — v5.6.0 Make sure that you're new:
- 📱 Libra is connected to your profile (in Devices) → Mi Body Composition Scale 2).
- 🔄 In the settings of the application, data synchronization is enabled.
💡
If the scales are not connected to the Mi Fit, try resetting them to factory settings: press and hold the reset button (under the battery compartment) for 10 seconds until the indicator blinks.
Official Calibration Method through Mi Fit
This is the most reliable method recommended by Xiaomi, which is suitable for 90% of users and takes no more than 5 minutes, and the instructions are relevant for versions of the application 4.6.0 and higher.
Step 1. Open Mi Fit and go to Profile section → Devices → Mi Body Composition Scale 2. Click on three dots in the upper right corner and select Calibration of the scales.
Step 2. Follow the instructions on the screen:
- Stand on the scales with bare feet (socks or slippers will distort bioimpedance).
- Stand still, do not talk or breathe deeply.
- Wait for the beep (squeak) and the message 100% on the scale screen.
Step 3: Repeat the measurement 2-3 times at intervals of 30 seconds, and the application will automatically average the data and save the calibration profile.
| Parameter | Normal value. | What to do if the deviation |
|---|---|---|
| Difference between measurements | ≤ 0.2 kg | Recalibrate or check the surface |
| Time for analysis | 8-12 seconds | Replace batteries or reset settings |
| On-screen message | 100% or OK | If Err - see the section "Calibration errors" |
If the scales are lying after calibration, try an alternative method (described below) or check the sensors for physical damage (e.g. cracks in glass).
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Calibration through Mi Fit resets the previous bioimpedance data, and after the procedure, the first 2-3 measurements may be slightly different — that's normal.
Alternative method: manual calibration through the engineering menu
This method is suitable for experienced users if:
- 📵 Libras don't connect to Mi Fit.
- 🔄 Calibration through the application does not give a result.
- 🛠️ You only need to calibrate the weight (without bioimpedance).
Attention! Incorrect actions in the engineering menu can result in a reset of all data or an Err 9 error. If you are not sure, use the official method.
Step 1. Enter the engineering menu.
- Then, put the weights on them.
- Hold the button. SET (under the battery compartment) for 5 seconds until the screen appears CAL.
Step 2. Calibrate the sensors.
- The screen will display the current calibration value (for example, CAL 50).
- Stand on the scale and wait for the numbers to stabilize (they should stop blinking).
- Press. SET again to preserve the meaning.
Step 3. Check. Take the weight off the scale and wait for 0.0. If the screen shows Err, repeat the procedure.
To reset to factory settings in the engineering menu, select RESET (hold on SET 10 seconds).
What to do if the scales show CAL, but don't save the settings?
Common calibration errors and their solutions
If you're calibrating an error code, don't panic. 95 percent of the time, the problem is solved without going to the service. Below is a table of the most common errors and the exact instructions for fixing them.
| Error code | Reason. | Decision |
|---|---|---|
| Err 1 | Uneven surface or vibration | Move the scales to the tile, check the level |
| Err 5 | Weak signal of bioimpedance (dry skin) | Wet your feet with warm water or use an ECG gel |
| Lo | Discharged batteries | Replace with new alkaline batteries |
| Err 9 | Failure of firmware or sensors | Reset the settings (hold on) SET 10 seconds) |
Err 5 is the most insidious error, and it happens when the skin's resistance is too high to avoid it.
- 🧴 Apply a thin layer of isotonic gel on your feet (sold in pharmacies for ECGs).
- 🧊 Wash your feet with a wet wipe (not wet!).
- ⚡ Stand on the scales with your bare feet, without socks.
Err 9 indicates a critical fault. If the reset doesn't work, check:
- 🔌 Battery contacts (clean alcohol from oxidation).
- 📶 Interference from other devices (disable the Wi-Fi router nearby).
- 🛠️ Integrity of sensors (when falling, plumes could move away).
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If the scales show Err 5 only in the morning, the problem may be dry skin after sleep.Try calibration in the evening or use a moisturizer 30 minutes before the procedure.
How to check the accuracy of the scales after calibration
Even after a successful calibration, you should make sure the scales are true, and use a control measurement with a known weight.
Method 1: Giri or dumbbells: Take an object with a known mass (e.g., a dumbbell 5 kg or a bag of sugar 1 kg) and the error must not exceed:
- ±0.1 kg for weights up to 10 kg.
- ±0.3 kg for weights of 50–100 kg.
- ±0.5 kg for weights over 100 kg.
Method 2: Cross-check, weigh on the Mi Body Composition Scale 2, and then on a mechanical medical scale (in the clinic or gym), the difference should not exceed 0.5 kg.
Method 3: Repeatability test. Weigh 5 times in a row at 10 seconds intervals. All values should differ by no more than 0.2 kg.
If the error exceeds the permissible values:
- 🔄 Recalibrate the calibration.
- 📲 Update the firmware of the scales through Mi Fit.
- 🛒 Contact the service center (if the scales are guaranteed).
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After calibration, the first 2-3 days of readings can “float” to the test. ±0.3 kg is normal. Sensors need time to stabilize.
Frequent questions about Xiaomi Mi Body Composition Scale 2 calibration
Can you calibrate scales without the Mi Fit app?
Why do the scales show 3 kg more after calibration?
How often should the scales be calibrated?
Can I use scales during calibration in socks?
The scale shows Err 5, what to do?
Weight Care Tips for Long-Term Accuracy
To make the Mi Body Composition Scale 2 last longer and not require frequent calibration, follow these guidelines:
1 Storage.
- 🏠 Keep the scales in a dry place (moisture) <60%).
- 🔥 Avoid direct sunlight and heat sources (batteries, heaters).
- 🧹 Regularly wipe the contacts (on the underside) with an alcohol wipe.
2. Batteries.
- 🔋 Use only alkaline batteries (e.g. Duracell Ultra).
- ⚡ Change all 4 batteries at once, even if only one is sitting down.
- 🗑️ Do not leave dead batteries in the scales - they can leak.
3. Measurements.
- ⏰ Weigh yourself at the same time (better on an empty stomach in the morning).
- 🧘 Stand on the scales motionless, do not talk or move.
- 📵 Disable other Bluetooth devices nearby (they may interfere with the device).
Updates. Check firmware updates in Mi Fit regularly. New versions often fix sensor errors.
- Open Mi Fit. → Profile → Devices → Mi Body Composition Scale 2.
- Click Update the firmware (if available).
- Do not interrupt the process, this can cause an Err 9 error.
5. Transportation. If you are carrying scales:
- 📦 Use the original packaging or hard case.
- 🚫 Do not put heavy objects on the scales (maximum load - 150 kg).
- 🔄 After transportation, be sure to repeat the calibration.
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If the scales have not been used for a long time (more than a month), before calibration, let them “warm up” in the room for 2-3 hours - this stabilizes the sensors.
Following these tips will extend the life of weights by 30-50% and minimize the need for recalibration. If accuracy problems persist, check the scales for warranty (the warranty period for Mi Body Composition Scale 2 - 12 months).