Think of it like trying to squeeze into your favorite pair of jeans from high school - it's just not going to fit, no matter how hard you try. Similarly, if your carry on bag is too big, it's not going to fit in the overhead bin, and you'll be forced to gate check it. This can be a real bummer, especially if you're someone who likes to have their essentials close by.
So, how do you measure your carry on bag? It's actually pretty straightforward. Most airlines have a standard size for carry on bags, which is usually around 22 inches tall, 14 inches wide, and 9 inches deep. You can use a tape measure or a ruler to check the dimensions of your bag and make sure it fits within these limits.