Understanding the world of mattress sizes can be confusing. Some terms mean one thing in the United States, and something else entirely in the rest of the world. Other terms, like “single” and “twin”, mean the same thing, but are both commonly used.

Is There a Difference?

“Single” used to be the more popular terminology, but today, “twin” is more commonly used. This is true in most countries, although some nations still prefer the term “single”. The term originally came about because hotels often placed two single beds – “twin” single beds – in the same room.

Some twin beds are designed to be bought and used in pairs. However, this is not necessary, and the dimensions of both twin and single beds are identical.

The twin bed size is generally 38 inches by 75 inches (sometimes 39 inches by 75 inches). This makes it the smallest mattress, outside of beds designed specifically for cribs and small children. It’s certainly designed for only one sleeper.

Trouble sleeping?

Answer these 5 easy questions to discover your perfect mattress

Trouble sleeping?

Answer these 5 easy questions to discover your perfect mattress

What position do you sleep in?

Side icon

Side

Side icon
Back icon

Back

Back icon
Stomach icon

Stomach

Stomach icon

Do you experience any pain while sleeping?

Back and/or side pain icon

Back and/or side pain

Back and/or side pain icon
Neck and/or shoulder pain icon

Neck and/or shoulder pain

Neck and/or shoulder pain icon
Little to no pain icon

Little to no pain

Little to no pain icon

Do you have any material preferences?

Innerspring icon

Innerspring

Innerspring icon
Foam icon

Foam

Foam icon
No preference/ Other icon

No preference/ Other

Do you sleep hot?

Yes icon

Yes

Yes icon
No icon

No

No icon

Do you sleep with a partner?

Yes icon

Yes

Yes icon
No icon

No

No icon

Back

Twin XL beds are a different size altogether, which can create some confusion. A twin XL is 38/39 inches wide by 80 inches long, giving it an extra 5 inches of legroom over the standard twin. Twin XL is a better choice for college students and adults over 6 feet tall. See our twin vs twin XL comparison for details.

We typically recommend twin beds for children and teens, and occasionally for single adults who don’t need a lot of space. Everyone else will be better off with a larger mattress.

Learn more about our Editorial Team

Learn More About Mattress Sizes and Dimensions

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What is a Double Bed?

By Austin Meadows June 12, 2023

What is the Size of a Queen Bed Frame?

By Lauren Fountain June 12, 2023

Twin XL vs. Full

By Logan Foley June 12, 2023

Oversized Mattress Sizes

By Logan Foley June 12, 2023

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