Ruler in Rhino

I can’t seem to find a ruler option on Rhino but I think this could be really helpful in the designing of a box project I am working on. Is this feature available, and if so, where can I find it?

Hi Addie - what do you want to accomplish? Some related features:

Length command
Distance command
The grid on the CPlane


also this might be handy:
and there is ScaleOverlay plugin by @lando.schumpich

which can be found here