What is Scale Metrics?

Scale Metrics is an iPhone app that records weight and body composition from Xiaomi Mi Body Composition Scale 2, plus manual body weight logging. It focuses on measurement history and trends, works 100% offline without an account, and keeps your health data private on your device.

How do you record a measurement?

Open Scale Metrics. Open the app on an iPhone running iOS 17 or later.
Step onto the scale or log weight. Step on your Mi Body Composition Scale 2 to sync via Bluetooth, or tap + to enter your body weight manually.
Review and compare. Review the saved measurement, then compare it with your history and trends.

Apple's Core Bluetooth framework allows iPhone apps to communicate with Bluetooth Low Energy devices. Scale Metrics uses that connection for compatible scale readings, then stores the resulting record locally.

Supported scale & manual weight logging

Scale Metrics is built for:

Mi Body Composition Scale 2: Instant Bluetooth Low Energy sync for stable weight and bioelectrical impedance estimates.
Manual Body Weight Entry: If you are traveling, using gym scales, or stepping on a non-Bluetooth scale, you can log your body weight manually with a single tap to keep your history continuous. (Note: manual entry accepts body weight only; bioelectrical impedance body composition metrics require stepping on a smart scale).

What measurements can the app show?

Available values depend on the data supplied by the scale and your profile. Scale Metrics can present:

Weight and BMI
Body fat and body water estimates
Muscle mass and bone mass estimates
Visceral fat, protein, basal metabolic rate, and body age estimates
A body score and metric-level insights

How should smart-scale estimates be interpreted?

Treat body composition values as estimates and look for patterns across repeated measurements. Bioelectrical impedance results depend on the device, prediction equation, individual characteristics, and measurement conditions.

A 2024 systematic review found that appropriate prediction equations depend on factors including device, age, ancestry, health status, physical activity, and sex. Earlier review evidence also found that longitudinal measurements under consistent conditions are more useful than isolated estimates.

How does the scale sync with the app?

When you step on your compatible Xiaomi scale with bare feet, the scale measures your weight and impedance and broadcasts the data over Bluetooth Low Energy. Scale Metrics receives the broadcast in seconds and saves it directly to your iPhone.

View Scale Metrics on the App Store ↗

How to track Mi Body Composition Scale readings