In Genesis, what was the ark’s length in cubits?

In Genesis, the ark’s length was three hundred cubits.

Genesis 6:15 gives the ark’s dimensions as 300 cubits long, 50 cubits wide, and 30 cubits high. The cubit was an ancient unit based approximately on the length of a forearm, but its exact historical measurement varied. For that reason, converting the ark’s dimensions into modern metres or feet involves an estimate.

Using a commonly proposed cubit of about 45 centimetres would make the ark roughly 135 metres long, 23 metres wide, and 14 metres high. Those conversions are approximations rather than measurements stated by Genesis.

The proportions create a long, rectangular vessel, and some modern discussions compare them with a stable barge-like design. Such comparisons are engineering interpretations, not proof that the narrative describes a historically documented ship. The unambiguous textual figure is the length: 300 cubits.