It's not always easy to grasp the size of features on the Moon. I've created both a "fixed scale" as well as a floating "bullseye" scale to help. You can set the number of rings visible through the Settings menu.
The scale is in miles if you choose imperial units in settings, and km if you choose metric. Note the bullseye scale "wraps" on the Moon, becoming foreshortened as you approach the limb. In reality, the ellipse is a circle, but it is seen a bit from the side, so appears squashed. The radius and length match the scale at the bottom, automatically re-sizing as the zoom factor is changed.
The numbers plotted here are the IKW Lunar Program features.