Box collider to measure

I normally add a box collider so that I can measure the dimensions of an object. Is there an easy way?

 

I usually see people say they place a 1 unit sized box next to the object, and either stack them or scale the box. But I like your box collider method.

I think though that there isn't an obvious way of doing this because it generally doesn't matter. Of course dimensions do matter, but relative to other elements in the game. So for example if you are trying to get the correct size for a door frame, what is important isn't that it is a specific number of units in size, but that it is the correct size for the characters which will pass through the doorway. So you compare against the character models instead of measuring. YMMV