How to set a specific edge length numerically? I've got this question from one of my best students. The question is the following:

Suppose, that we have Edit mode with some edges, vertices, etc. How to set a selected edge to have a specific length? Numerically?

We already know, that scaling with enabled 'Show edge length' is helpful, but in general, it seems to be easier to just select an edge, and to set its length. This is extremely useful for architecture modeling.
This feature is now in an included addon in Blender 2.79 called Mesh: Edit Tools 2. You have to enable the addon in the User Preferences.




Go to Add-ons
Search "edit"
Click the box for Mesh: Edit Tools 2
Save User Settings




While in Edit Mode, press W for the Specials Menu


Edit Tools > Set Edge Length
Input a target length and click OK.


Hope this helps! I searched forever to find the answer. Shoutout to Danyang Yi for providing the link to a previous version of this addon prior to it being included in Blender.