The US size is first and UK is second the cups are the same F is E, G is F, H is FF, I is G, J is GG, K is H,L is HH, M is J, O is JJ FANTASIE OF ENGLAND 4500 SMOOTH UP TO G CUP UK SIZING FANTASIE OF ENGLAND 6500 UP TO GG UK SIZING NEW FANTASIE MARIETTE 6102 BALCONY UP TO J UK SIZING NEW FANTASIE MARIETTE BALCONY 6103 UP TO G UK SIZING NEW FANTASIE MARIETTE 6112 UP TO GG CUP UK SIZING FANTASIE GABRIELLE 6303 UP TO J CUP UK SIZING NEW FANTASIE GABRIELLE 6323 BALCONY UP G CUP UK SIZING NEW FANTASIE GABRIELLE 6302 FULL CUP UP TO G UK SIZING FANTASIE ALLURE MOULDED BALCONY 7110 UP G CUP UK SIZING FANTASIE BELLE 6001 FULL CUP UP TO JJ UK SIZING FANTASIE BELLE 6000 FULL CUP UP TO G UK SIZING ELOMI JASMINE 8410 UP TO H CUP UK SIZING ELOMI KRISTIE 5810 UP GG CUP UK SIZING ELOMI TAMARIE 8020 UP TO GG CUP UK SIZING ELOMI CAITLY 8030 UP TO HH CUP UK SIZING ELOMI CLEO 8000 UP H CUP UK SIZING Any questions? Please call us at 1-800-858-3887.