Standard Adult Bunk Bed Sizes

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Bunk beds are a good space-saving solution that only come in two sizes. Bunk beds are closely related to children who share a bedroom in a small home or roommates in a dorm who share a room. Bunk beds that are strongly constructed can hold the average adult, but the size of the bunk bed will still be limited.

Bunk Bed Sizes

Bunk beds come in two sizes, either a twin or full size mattress. A twin mattress measure 39 inches wide and 75 inches long and a full size is the same length, just wider at 54 inches. Bunk beds are sold in twin bed over twin bed, twin bed over full size bed or full size over another full size bed. Full size beds are ideal for adults because they provide a larger area of sleep over twin size mattresses.


The frame is best constructed from hardwoods such as oak, maple or cherry woods for their increased durability and longevity. Adults weigh more than children and will need a strong bed frame for bunk beds. Avoid particle woods and metal frames, which are cheaper but are much less supportive. These frames will not hold up over time. Hardwoods are heavier and can handle more stress without cracking, a much needed element for an adult bunk bed.


Bunk beds save space. However, a sturdy base, especially for a full-size bunk bed is imperative to ensure the safety of not only the person on the top bunk but the individual below as well. Climbing up and down a sturdy ladder with a strong base is just as important as crash barriers. These will prevent you from tossing and turning and possibly falling from the top bunk.


A foundation that is the same size as the full size mattress will be needed for a bunk bed. A metal bunk bed often has a foundation built into the frame and will eliminate the need for an independent foundation. For frames without a built-in foundation, wooden slats can be installed or more commonly bunk boards are used. A bunk board is basically a thin flat piece of wood capable of providing a foundation to the bunk beds. Slats made of hardwoods, however, are a better option for an adult..