Fundamentals > Creo Parametric User Interface > The Analysis Tab > Measuring Geometry > Measuring Entities > Using Specific Measurement Types > Distance > Using Reference Entity Options > About the Axis Option
  
About the Axis Option
If you select a cylindrical shaped surface, with the Axis option you can measure the distance from the central axis of the cylinder formed by the surface. Clear this option to measure from the surface instead of the axis.