In Genesis, the stated height of Noah’s Ark was 30 cubits.
Genesis 6:15 gives the ark’s three principal dimensions as 300 cubits long, 50 cubits wide, and 30 cubits high. A cubit was an ancient length measurement based approximately on the distance from an elbow to a fingertip, but its exact size differed across historical cultures. With a common estimate of about 45 centimeters, 30 cubits would be approximately 13.5 meters.
The height should not be confused with the number of decks. Genesis separately says the ark had lower, second, and third levels. Nor does the text state that the vessel had a pointed ship-like hull; its dimensions describe a large enclosed structure built for survival on flood waters.
Because cubit standards varied, any modern conversion is approximate. The biblical number itself, however, is explicit: 30 cubits.