Typically the map units displayed in the status bar and used in the legend are in miles or kilometers. You can change the default units as follows:
- Choose Edit>Preferences to display the User Preferences dialog box.
- Click the System tab.
- Choose a unit of measure from the Map Units drop-down list, and optionally, choose the language to use in the legend for the units from the Language drop-down list.
You can also manually customize your text, see Customizing a Legend for more information.