Adjust the type of units used for your height, weight, water consumption, temperature, and swims.
Note that for Fitbit Aria Air you can tap the button on the back of the scale to switch between pounds, stones, or kilograms.
Fitbit app
If you sign in with your Google Account
- From the Today tab
in the Fitbit app, tap your profile picture
Fitbit settings.
- In the App Settings section, tap Date, time & units.
- In the Units of Measurement section, tap the unit you want to change and select the new unit.
- Sync your Fitbit device.
in the Fitbit app, tap your profile picture 
Fitbit settings.If you sign in with your Fitbit login
- From the Today tab
.
- In the App Settings section, tap Date, time & units.
- In the Units of Measurement section, tap the unit you want to change and select the new unit.
- Sync your Fitbit device.
For Aria 2, you can also change the units shown on the scale:
- From the Today tab
- Tap Weight Units.
- Choose the units you want the scale to show your weight in. The next time you sync your scale, you’ll see your weight in the units you select. You may have to weigh yourself twice before you see the units update.
fitbit.com
- On the Fitbit settings page, scroll down to the Advanced Settings section and click Units.
- Choose the type of units you want to use.
- Click Submit.
For Aria 2, you can also change the units shown on the scale.
- On the Fitbit settings page, click your scale under the Devices menu.
- Click the button next to Scale Units.
- Choose the units you want the scale to show your weight in. The next time you sync your scale, you’ll see your weight in the units you selected. You may have to weigh yourself twice before you see the units update.