If you use two twin-sized bed frames, they’ll shift apart from each other while you’re sleeping unless you secure them to each other. Switching to a king-sized bed frame is a better long-term option.
If you’re using XL twin mattresses, your new bed will be the exact same length as a king-sized bed—80 in (200 cm). However, if you’re using standard mattresses, they’ll be about 5 in (13 cm) shorter. [3] X Research source
You can buy these wedges online or at big-box home stores. The center of the bed might be slightly higher than the sides at first, but over time, it will become less noticeable as the foam forms to the shape of the gap.
If you used two standard mattresses, place the mattress topper so it hangs evenly over the top and bottom of the bed. That will help disguise some of the difference in length, especially when you put your sheets on the bed! However, if you don’t want to use a topper, just tuck the sheets a little further under the mattress. [6] X Research source
You can buy twin bed conversion kits at many home stores—they’ll include both the straps and the foam wedge. If you don’t have a foam wedge, place folded towels in the gap, then cover them with a folded quilt. However, keep in mind this may not be the most comfortable solution. This is a great option if you’re using two twin beds in a guest room and you’d like the option of converting them into one larger bed when company comes.
You could even clamp the frames together if you happen to have a couple of C-clamps available.
You’ll have a gap running horizontally along the bed, so this isn’t necessarily the most comfortable option. However, it can work if you really don’t want to sleep all night in a twin bed!
