Build your own Bunk Beds Toddler Size! In this post I provide the measurements I used to build bunk beds to fit toddler sized mattresses and link to the plans that I modified to build these toddler bunk beds. When we were expecting our third child we lived in a small apartment at the University of Utah. The apartment was great, but the bedrooms were small, so to maximize space we wanted to have our 5 year-old and 3 year-old use a bunk bed that would accommodate the smaller toddler size mattress. We searched all over and could not find anything, not just anything affordable, but nothing at all! Turns out toddler size bunkbeds can't be sold because of some regulation or another. So we decided to build our own. This was my first real building project and other than one shop class in 7th grade I haven't done a lot of work with wood. I did enlist the help of a friend who had worked quite a bit with wood and who had a lot of the tools. We started by choosing a straight forwa...