Printing Actual Size

I am trying to print a drawing that prints “Actual Size”. For example I draw a Circle with a 2 inch radius and when I print it the radius is 1 inch.

Your statement is vague.
Are you talking about 3D printing or printing on paper?

No just simply want to print a 4 inch diameter circle. Trying to create an overlay for my speedometer that displays KPH as opposed to MPH.

See…
Printing to Scale — SketchUp Sage Tutorials