Yes. Your mattress height is a big part of your bed’s height. Depending on its thickness, your mattress can add anywhere from nine to 15 inches to the overall height of the bed. That means if you have an 18-inch bed frame, a nine-inch foundation, and a 12-inch mattress, the overall height of your bed will be 39 inches. You’ll need to add all three components together to get the total height of your bed.