Cambridge is about 45 minutes by train (longer if you drive) north of London. Oxford is about the same but west of London. I am not sure if they have a train that connects the cities. I would assume it would be a good amount of time to travel from one to the other by car or by train, at least an hour I am guessing. I have never been to Oxford but the Cambridge campus is beautiful.

If you are talking about Cambridge in MA, it is near Harvard in Boston, Oxford, Ma is about 30 minutes off the Ma pike from Cambridge.

they aren’t massively far from each other, i’d take a guess of 50 miles or so. how long it takes to get from one to anothe will depend whether you’re driving, going by train, walking, or using a horse and carriage (very popular in england).