As with any bed, the final dimensions will depend upon the mattress you choose to purchase. Lengths and widths are standard but thicknesses vary considerably. I will build the bed frame to accommodate the mattress thickness you chose as well as the height that you wish the mattress top to sit from the floor. With this style of bed I specify one wide board for the headboard, about 17" W. The bed is securely assembled with 4 special bolts and a wrench that I supply.