Scale Relay | Xiaomi scales to Garmin Connect

Version 1.2 · S400 support

Your Xiaomi scale. Your Garmin data.

Scale Relay reads weight and body composition directly from supported Xiaomi scales and sends the measurement to Garmin Connect from your iPhone.

Download on the App Store<br>Check compatibility

Free to try · Garmin sync is a one-time purchase.

Compatibility

Two supported Xiaomi scales

Scale Relay recognizes the correct Bluetooth protocol automatically.

New in 1.2 · MJTZC01YM

Xiaomi Body Composition Scale S400

Weight and body composition after a one-time Xiaomi authorization.

S400 setup guide →

Supported

Mi Body Composition Scale 2

Weight and body composition with direct local detection. No Xiaomi account required.

Scale 2 setup guide →

How it works

From scale to Garmin in three steps

01

Open the app

Scale Relay listens for your scale over Bluetooth.

02

Step on the scale

Stand still and barefoot until the measurement finishes.

03

Send to Garmin

Review the result and upload it to Garmin Connect.

Privacy Policy & Support

Privacy Policy

Last updated: August 6, 2026

Scale Relay is designed with your privacy in mind. Scale readings are processed locally on your device and are not stored on Scale Relay servers.

Bluetooth

The app uses Bluetooth to read measurements from supported scales. Weight and impedance are processed locally to calculate body composition metrics.

Accounts

Garmin Connect is used only when you choose to upload a measurement. The Xiaomi Body Composition Scale S400 requires a one-time Xiaomi authorization to retrieve its Bluetooth encryption key. Authentication data is stored in the iOS Keychain.

No analytics or tracking

Scale Relay does not include analytics, advertising, or tracking frameworks.

Contact form

If you use the website contact form or the optional feedback form in the app, we receive your message and any email address or scale model you choose to provide. App diagnostics are included only with your permission and never contain measurements or authentication data. Messages are delivered through a Firebase Function and Resend and are not used for analytics or advertising.

Support

Need personal help, want to share feedback, or have a scale you would like us to support? Contact us.

Supported models:

Mi Body Composition Scale 2

Xiaomi Body Composition Scale S400 (model MJTZC01YM)

Common issues:

Scale not detected: Enable Bluetooth, open Scale Relay, and wake the scale by stepping on it.

No body composition: Measure barefoot and remain still until the measurement finishes.

S400 setup: The S400 must already be paired in Xiaomi Home before one-time authorization in Scale Relay.

Disclaimer: Scale Relay is an independent app and is not affiliated with, endorsed by, or sponsored by Garmin Ltd., Xiaomi Inc., or Apple Inc. Garmin and Garmin Connect are trademarks of Garmin Ltd. Xiaomi and Mi are trademarks of Xiaomi Inc. Apple and iPhone are trademarks of Apple Inc.