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 NEW GODDESS 3911 SEAMLESS MOULDED GG UK SIZING FANTASIE OF ENGLAND 4500 SMOOTH UP TO G CUP UK SIZING FANTASIE SMOOTH BALCONY 4520 UP TO G CUP US SIZING ANITA SMOOTH 5444 UP TO G CUP US SIZING NEW GODDESS 1220 SEAMLESS MOLDED UP H CUP UK SIZING WACOAL 85185 SMOOTH UP TO DDD CUP US SIZING WACOAL NO WIRE MOULDED 32-40 B TO D CUP US SIZING FELINA MOULDED 6301 UP TO DD CUP US SIZING FANTASIE ALLURE MOULDED BALCONY 7110 UP G CUP UK SIZING ABC 106 SOFT NO WIRE MOULDED AA TO DD UP 54 US SIZING ABC 103 NO WIRE MOULDED UP DD CUP US SIZING GODDESS 3910 SMOOTH UP FF CUP UK SIZING Any questions? Please call us at 1-800-858-3887.