Well, for one, you don't want to have to gate check your bag, which means you'll have to pick it up at the baggage claim, and that can be a hassle. Plus, if your bag is too big, you might have to pay extra fees, and who wants that? It's like trying to squeeze into a pair of jeans from high school, it's just not gonna happen, and you'll end up frustrated.
So, how do you even measure your luggage to make sure it fits? It's actually pretty easy, just grab a ruler or a measuring tape, and measure the height, width, and depth of your bag. You can even use a carry on size chart template that you can find online to help you out. It's like measuring a room for furniture, you gotta make sure it fits, or it's just not gonna work.
Now, I know what you're thinking, what if my bag is just a little bit too big? Can I still bring it on? Well, it's not worth the risk, because if it doesn't fit, you'll have to check it, and that can be a pain. Plus, some airlines have strict policies about carry-on size, so it's better to be safe than sorry. It's like trying to sneak a extra carry on onto the plane, it's just not gonna fly, pun intended.
Carry-On Luggage Size Chart - know the correct dimensions