In the Book of Genesis, how many cubits long is Noah's Ark?

In the Book of Genesis, Noah's Ark is described as 300 cubits long.

Genesis 6:15 gives the Ark's dimensions as 300 cubits in length, 50 cubits in width, and 30 cubits in height. Because a cubit was an ancient unit based broadly on forearm length, its exact modern equivalent is uncertain. Using common estimates, the Ark would have been roughly 135 metres long, though calculations vary.

The proportions are often compared with those of a large ship: the length-to-width ratio is 6:1. Modern naval design commonly uses different proportions, but the biblical measurements create a long, substantial vessel. The text says the Ark was made from “gopher wood” and coated with pitch to make it watertight.

These dimensions belong specifically to the Genesis account. Later Jewish, Christian, and Islamic traditions add details, while popular artwork often presents the Ark with shapes and features not specified in Genesis.