In the Book of Genesis, Noah's Ark had three floors.
Genesis describes the ark as having lower, second, and third decks. The layered design is presented as part of the vessel's construction instructions, alongside its rooms, window, and door. The text does not provide a modern naval blueprint, so the exact arrangement of the decks is unknown.
The three-level detail is easy to confuse with other ark numbers. Genesis gives the ark a length of 300 cubits, a width of 50 cubits, and a height of 30 cubits. It also says that Noah was instructed to make it from gopher wood and to coat it with pitch inside and out.
Later Jewish, Christian, and Islamic traditions add interpretations about the ark's structure, but the three-floor description comes specifically from Genesis. The account's emphasis is on the vessel's enormous size and its role in preserving Noah's family and the animals during the flood.