In the biblical Book of Genesis, what was the ark's length in cubits?

The Book of Genesis gives Noah's Ark a length of 300 cubits.

Genesis 6:15 records the ark's three principal dimensions as 300 cubits long, 50 cubits wide, and 30 cubits high. The text presents these measurements as God's instructions to Noah before the Flood.

A cubit was an ancient unit based broadly on the length of a forearm, so its exact modern equivalent is debated. Depending on the cubit used, 300 cubits is often estimated at roughly 135 to 157 metres. The biblical passage does not specify a modern unit or the cubit's exact length.

The length is sometimes confused with the ark's width or height. In the same verse, the width is 50 cubits and the height is 30 cubits. These proportions have also inspired later studies and reconstructions of the vessel's stability.