I have yet to see an airline check-in counter measure the dimension of the check-in luggage. They will weight it and if it is more than 1lb over, they will make you take things out, but I have not seen any of them actually take out a measuring tape to measure it. Mine was just under the max size of most US airlines and there are at least 30% of the luggages on the belt that are larger than mine. And some of them are WAY larger.