While it's always a safe bet to get a bag the same size as your laptop, we actually recommend going for bigger bags and briefcases, in most cases. This is because a larger bag allows you to carry more valuables and accessories, plus, if you decide to get a bigger laptop in the future, you want your bag to be able to fit it. Of course, you should still make sure your bag or backpack is not too big for your laptop as you don't want your pricy system to clang around in there.