According to Genesis, what was the approximate length of Noah’s Ark?

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

Genesis 6:15 gives the ark’s dimensions as 300 cubits long, 50 cubits wide, and 30 cubits high. Because the ancient cubit is a body-based unit whose exact length varied, converting the measurement into metres or feet is approximate.

Using a common cubit estimate of about 45 centimetres gives a length near 135 metres, or roughly 450 feet. Other estimates produce somewhat different totals, so “300 cubits” is the precise textual answer and a modern conversion should be treated as an approximation.

The dimensions create a long, boxlike vessel rather than a conventional sailing ship. Genesis emphasizes containment and survival during the flood; it does not describe sails, oars, a rudder, or a navigational route.