Meanings
Originally with reference to the fact that if one owed a penny, one might as well owe a pound (pound sterling, UK currency) as the penalties for non-payment were virtually identical in severity.
How to pronounce "in for a penny, in for a pound":
AU
Having started something, one must see it through to its end, rather than stopping short; one must “go the whole hog”.
Example Sentences
1
He already maxed out his credit card, so he figured in for a penny, in for a pound and bought the expensive handbag too.
2
Once she agreed to bake a cake for the party, she thought in for a penny, in for a pound and decided to make the whole dessert spread.
3
They were already running late, so they decided in for a penny, in for a pound and took the scenic route to enjoy the drive.
4
I was planning to have just a bite, but when I saw the dessert menu, I thought in for a penny, in for a pound and ordered a whole slice of cake.
5
He knew he would have to work late, so he thought in for a penny, in for a pound and accepted the additional project too.