In a nutshell: Yes — as long as it's a soft-case, and as long as you don't overpack it, say Salem and Bradford. Garland adds that you may get away with it if it's an airline you're familiar with and know that they don't look too closely at carry-on size. But she gives a big "but." "Be aware that some airlines really do check closely, especially low-cost carriers, and if your bag is too big, they will make you check it, sometimes with a fee," Garland says. "If that happens, then you have to take out things like electronics, medicine and other valuables you won't want lost or damaged, which can get awkward if you don't have another bag to put them in."