In steps:
Click on your name (top right of the page);
Click on Settings;
In the “Professional information” section, click on Unit system. You can then choose between metric (meter, kg, etc.) and imperial (feet, pounds, etc.).
Further information
By default, the client obtains the same unit system and the same language as the professional who created his account.
However, he can make the modification on the application. To find out more, click here.