Single beds, more commonly referred to as twin beds, are the perfect size to combine to create a larger bed, such as a king size bed. Two identically sized single beds and a bed frame should be used to create the new bed for a guest room or to upgrade your own bed size.
Use two single beds with identical dimensions. It's especially important for the two beds to have the same height and length to create a comfortable and even sleeping surface. Width isn't as important because there are sheets and bed frames that can fit most widths.
Measure the full dimensions of the two full beds pushed together lengthwise. Then, get the appropriately sized bedding and bed frame.
Set up the bed frame and place the two single beds parallel lengthwise on the frame, being sure to place them as closely together as possible in order to seal the crack between the two beds.
Install a bed bridge to hold the two beds together. There are numerous bed bridges available that help seal the space in between the two beds. Many can be purchased online or at home furniture stores. If you opt to not use a bed bridge, skip this step. Some bed frames can help keep the beds pushed together so bed bridges aren't always needed.
Place the bedding on the two singles to finish setting up your new bed.