Genesis uses the cubit when giving Noah’s Ark its dimensions.
Genesis 6:15 specifies the Ark as 300 cubits long, 50 cubits wide, and 30 cubits high. A cubit was an ancient measure generally based on the length of a forearm, from the elbow to the fingertips. Its exact value varied across cultures and periods, so the biblical measurements cannot be converted into one universally certain modern figure.
Using a commonly proposed cubit of roughly 45 centimeters, the Ark would be about 135 meters long, 22.5 meters wide, and 13.5 meters high. Other estimates produce somewhat different results. The proportions, however, remain approximately 6:1 in length to width.
The cubit is not unique to the Noah narrative. Ancient Near Eastern texts and the Hebrew Bible use related measurement systems in descriptions of buildings, land, and objects. The Ark’s dimensions should therefore be read as an ancient textual specification rather than as a precise modern engineering blueprint.