If you have unexpected company, or just need to furnish a spare bedroom, there is no need to go out and buy a king size bed. Instead, you can easily make a king bed out of two twins. Using two single beds to make a king is cost efficient and practical because the beds can also be separated for guests who need to sleep alone.
Arrange two twin size box springs so they are directly next to each other lengthwise. Push the beds as close together as possible.
Place two twin size mattresses on top of the box springs. Use a twin bed bridge to connect the mattresses. Slide the connector foam in between the beds, and then wrap the straps around the edges of the mattresses. Tighten the straps so they fit tightly around the sides.
Place the foam topper on top of the twin beds and line up the edges. Cover the bed with king size sheets and a king size comforter.
Another way to keep the beds together is to lay the mattresses on top of the box spring in the opposite direction, so they form a cross. This will hold the mattresses together as well.