Change the length (scale) of normals in the display

User Guide > General > Basics > Preferences and customization > Customize the look and feel of the interface >

Occasionally you may want to change the length of normals (lines indicating the normal direction of a face or vertex) to make them more visible or less distracting. You can change the scale of normals on a per-object basis.

To...	Do this
Change the size of normals on polygonal surfaces.	Show the Attribute Editor for the surface. Open the Mesh Component Display section. Turn on Display Normal and set the Normal Size.
Change the size of normals on subdivision surfaces.	Show the Attribute Editor for the surface. Open the Subdiv Surface Display section. Set the Normals Scale.