According to Genesis, how many cubits long was Noah’s Ark?

According to Genesis, Noah’s Ark was 300 cubits long.

Genesis 6:15 gives the vessel’s dimensions as 300 cubits in length, 50 cubits in width, and 30 cubits in height. The passage supplies proportions rather than a modern measurement, because the exact length of a biblical cubit is uncertain and may have varied by period and region.

Using a commonly cited cubit of roughly 45 centimetres would make the Ark about 135 metres long, but that conversion is approximate. The biblical dimensions produce a long, rectangular vessel rather than the boat shape often shown in paintings. Genesis does not say that the Ark was designed to sail to a destination; its stated purpose was to preserve life during the Flood.