An inside cabin will be the smallest on a ship, and it generally has no window. It's sort of like being in a closet but with a major benefit: It's usually the cheapest cabin on any ship.

On almost every cruise ship, the Interior (Inside) Cabin is the smallest and most compact accommodation type. These rooms are located in the middle of the ship's decks and have no windows, portholes, or balconies leading to the outside. A typical interior cabin in 2026 averages between 140 and 160 square feet. However, some newer "mega-ships" have introduced an even smaller category known as the Studio (Solo) Cabin, designed specifically for single travelers. These studio rooms can be as tiny as 100 to 120 square feet, focusing on efficiency with clever storage and often a full-sized or "XL" twin bed. While they are the smallest, they are also the most budget-friendly and are ideal for passengers who only plan to use their room for sleeping and showering. Interestingly, some Royal Caribbean ships offer "Virtual Balcony" interior rooms, which are the same small size but feature a floor-to-ceiling LED screen displaying a real-time high-definition view of the ocean to make the compact space feel less enclosed.