According to Genesis, what was the total length of Noah's Ark?

According to 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. The cubit was an ancient unit based broadly on the length of a forearm, so its modern equivalent is uncertain. Depending on the cubit used, 300 cubits is often estimated at roughly 135 metres, though calculations vary.

The proportions make the Ark an exceptionally long, low vessel compared with a typical houseboat. Modern replicas, including the Ark Encounter structure in Kentucky, use one chosen modern conversion, but such projects are interpretations rather than evidence of the original vessel's measured size.

The dimensions are sometimes remembered as 300 by 50 by 30, but the question asks only for length. Width and height are separate figures, and none should be substituted for the 300-cubit length.