Mine are the same size but my best friends are more than a cup sized different. It bothers her a lot....moreso when she was younger. It's pretty common from what she tells me. Her breasts don't look so noticeably different to me but I can tell a bit. Do bra makers make bras with different sized cups? If not, someone should start a custom bra ordering company to help women with this issue. Finding comfortable bras is hard enough without having to deal with this problem.