How do I change the units of measurement in my Fitbit account?

[Sweatysock]

How can I change distance measured from kilometres to miles ? 

Moderator Edit: Clarified subject

[SteveH · Accepted solution]

One way of doing this is via your profile settings on the web interface at https://www.fitbit.com/settings/profile

In the Units section change the "length" unit from "centimeters" to "Feet/inches"

Once changed and saved, the next time you sync your fitbit will be updated.