In Genesis, how long was Noah’s Ark?

In Genesis, Noah’s Ark was 300 cubits long.

Genesis 6:15 gives the Ark’s three principal dimensions as 300 cubits in length, 50 cubits in width, and 30 cubits in height. A cubit was an ancient measurement commonly based on the length of an arm, so its exact modern equivalent is uncertain.

Using a commonly cited cubit of about 18 inches, the Ark would have been roughly 450 feet, or 137 meters, long. Other proposed cubit lengths produce somewhat different conversions, which is why translations generally preserve the ancient unit.

The proportions make the biblical Ark a long, box-like vessel rather than a conventional ship with a pointed bow. Modern replicas often use the Genesis dimensions, although their materials, interiors, and engineering systems are not part of the biblical account.