Hi

please could someone guide me on crocs sizing

i am usually a uk 4 size but i fit perfectly into my sons crocs athens which are marked m3 w5,they are supposed to be a uk 3.

i am looking to buy womens'crocs cleo and they only have size uk 3 left.will a 3 fit me as the athens style clearly did or are the cleos' sized differently?

any help appreciated.thanks