This utility rescales the world units of either the entire scene or selected objects in the scene. The Rescale World Units dialog controls scale factor and whether it is applied to the entire scene or the current selection.
Utilities panel > Utilities rollout > More button > Utilities dialog > Rescale World UnitsTo rescale an object:
Select an object in the viewport.
Utilities panel, click the More button, and on the Utilities dialog, choose Rescale World Units from the list.
After selecting the objects you want to rescale, click this to display the Rescale World Units dialog.

Specifies the scaling factor.