This is the only method I know of. This works on ANY face if you chose a face.
Notice that in this example I have a surface since the question was for a surface. This Centroid lesion will works on any face or body... the result depends on what you select in the next step.
Go to Sections Properties under the tools menu.
Select your face (or body as previously mentioned). Note that you could also have it pre-selected before clicking the Section Prop. button. To change your result simply clear out the selected items in the box circled. When the object you want to query is there hit Recalculate.
Now you get a load a info, with the Centroid(relative to the sys. orgin) info circled.