Megabites to gigabyte on iPhone 4?

So I went over my data in the iPhone today and they said my overage was 74 and I wasn't sure what that meant when they wrote it was it in megabites? Anyways I still have a week to go for it and will they charge since I went over 74? Or will they not?

Well the safe assumption was that you went over by 74MB which is 0.0722656GB. More than likely you would be charged.