Genesis uses the cubit to state Noah’s Ark’s dimensions.
Genesis 6:15 gives the Ark as 300 cubits long, 50 cubits wide, and 30 cubits high. A cubit was an ancient unit based broadly on the length of a forearm, so its exact value varied across cultures and periods.
Because there was no single universal cubit, modern conversions are estimates. A commonly used approximation is about 45 centimeters, which would make the Ark roughly 135 meters long, 22.5 meters wide, and 13.5 meters high. Other proposed values produce somewhat different figures.
The dimensions have also prompted comparisons with the proportions of ships and barges. Genesis, however, gives no modern-unit equivalent and does not describe the Ark as a conventional sailing vessel; the story presents it as a vessel designed to survive the floodwaters rather than to navigate under its own power.