Definition
This idiom suggests that when the consequences for a minor offense are the same as those for a major offense, there is no reason not to commit the greater one.
Since I'll get fired whether I'm five minutes late or thirty minutes late, I might as well be hanged for a sheep as for a lamb and just arrive an hour late.
"Since I've already been caught stealing one piece of candy, I might as well be hanged for a sheep as for a lamb and take the whole jar," he said, grabbing the entire container of sweets.
Since we’ve already gone over budget for this project, we might as well be hanged for a sheep as for a lamb and add a bit more resources, hoping to ensure its success, the punishment would be the same anyway.