Although there are numerous sites presenting differences between these two variants of the English language (I have also reviewed one of those websites here), there is a simple way to find out whether a word or a phrase is used (more frequently) in British English or in American English.
Open the COCA (creating a login is strongly recommended as this allows for a unlimited number of queries) Enter the term or phrase you want to researchAnd then click on the green box on the upper right-hand corner and select BNC (British National Corpus)
What you will get are numbers of occurrences of your term in the two corpora. More details about the COCA and the BNC can be found here and here.