The outer rim of Babbage has been eroded and modified by a multitude of subsequent impacts, until all that remains is a ring of rounded hills.

The northeast rim of this satellite crater is missing, and it forms a bay on the perimeter of Babbage.

The outer rampart of Pythagoras lies across the floor of Babbage, forming a region of rough terrain in the northwest part of the interior.

The most notable feature on the floor is the satellite crater Babbage A, which lies in the southeast part of the interior.

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Babbage.