ContactsRuler

This ULP makes measuring distances between footprint contacts easier You can use this in the Library and board editors

Usage in the Library editor:

Using the group tool, select any 2 of the following: pads, smds, holes and lines.
Run ContactsRuller.ulp
You will have the X and Y result difference in 3 different units: mm, mil and inch.

Note: Don't select more than 2 objects in the group.

Usage in the Board editor:

Using the Group tool, select the part you want to measure, for the distance between its pads.
You will will then have a dialog with check box beside each contact name.
Select any 2 contacts.
Press OK. Next you will have a dialog with the difference in X and Y in 3 units: mm, mil and inch.

Note: Don't select more than 1 part in the group, and don't check more than 2 boxes in the dialog screen.

Usage: RUN ContactsRuler.ulp