When people first shop for bedding, many are surprised to learn how many different mattress sizes there are. They are also surprised to learn just how widely bedding sizes can vary. It’s easy to get confused about how to match bedding sizes and bed sheet sizes with the many different mattress and bed dimensions there are.

In this guide we detail standard North American mattress dimensions and show the bedding sizes that work best with each of them.

When shopping for bedding, you have some room for error when it comes to the size of duvets, comforters and flat sheets, but not fitted sheets. How much room you have depends on how far the top of your bed is from the floor. Bedding that is too wide will drape onto the bedroom floor. To get your maximum bedding width, measure the distance from the top of your bed to the floor, double it, and add the width of the mattress.