In Genesis, what were the ark’s stated dimensions in cubits?

In Genesis, the ark’s stated dimensions were 300 by 50 by 30 cubits. Genesis 6:15 gives the order as length, width, and height, making the vessel much longer than it was wide or tall.

A cubit was an ancient unit based broadly on the length of a forearm, so its exact measurement varied by culture and period. For that reason, the biblical text gives the original dimensions without fixing one universally accepted modern conversion. Estimates commonly place the ark at roughly 135 metres long, but the conversion depends on the cubit used.

The proportions are approximately 6:1 in length to width and 10:1 in length to height. Modern naval engineering discussions sometimes note that these proportions would favor stability, although that does not establish that the biblical vessel existed as a historical ship.

Genesis also says the ark had three decks, rooms, an opening, and a door. Those details are separate from its basic numerical dimensions.