To seem very likely from the known facts; to be clear and logical.
This idiom is almost always used with the pronoun subject it and is followed by a that clause.
It stands to reason that a person without experience cannot do the work as well as an experienced one.
It stands to reason that he isn't going to pass the course if he never studies.
If you have a driver's license, it stands to reason you can drive.
Joe is intelligent and studies hard; it stands to reason that he will pass the examination.