System Information
Windows 10
Blender Version
2.78
Short description of error
No place to change units in MeasureIt
Units changed to inches in Blender, but show up as meters in MeasureIt
Exact steps for others to reproduce the error
Change Units in Blender for object to inches
Select two vertices and select Seg / Show in 3DMeasureIt
The unit setting needs to be set in the Properties region of the Viewport (N-Panel).
The panel will show up if you have added a measurement to an object.
Setting it to Automatic should take the Blender scene units automatically (the other settings are independent of the Scene settings)
If that doesn't work, please can you provide additional information:
What version of the add-on you're using?
The latest one is 1.6.8 updated on October 1st.
Can you try the latest developer build from here (latest MeasureIt is shipped with it) and see if it works for you?
https://builder.blender.org/download/
More than a week passed without a reply.
Due to the tracker policy, archiving until the required additional information / data is provided.