Intuitively, the different sizes of beds seem easy enough to understand, right? The truth is, choosing the right size of your mattress can be more complicated than you may think. Does it fit nicely in my bedroom? Is there enough leg room? And many others. To help you make the best decisions when selecting a mattress, we’ve put together a summary of the most common measurements you will see online and in a store so you can have an idea if it’s a perfect bed for you and your bedroom.