What is the mattress size for a twin mattress?

Twin-size mattress is a wider cousin of Single-size mattress. Ideal for single adults and small spaces, Twin-size mattress can also fit in well in a room measuring at least 10.5 feet by 8.5 feet. Twin-size mattress gives you extra width to stretch yourself while sleeping and allows you to be a little more carefree with the space on your bed.