Genesis gives Noah’s Ark a total length of 300 cubits. Genesis 6:15 also specifies a width of 50 cubits and a height of 30 cubits, creating the text’s only detailed dimensions for the vessel.
A cubit was an ancient unit commonly associated with the length of a forearm, but its exact value varied by time and culture. Depending on the cubit used, 300 cubits is often estimated at roughly 135 to 157 metres, or about 450 to 515 feet. The biblical text itself does not convert the measurement into modern units.
The Ark’s stated proportions are approximately six to one in length versus width and ten to one in length versus height. Modern discussions sometimes compare those proportions with stable ship designs, but Genesis presents the Ark primarily as a divinely instructed refuge rather than as a documented historical shipwreck or surviving archaeological object.