How far above the mountains did Genesis say the Flood waters rise?

Genesis says the Flood waters rose 15 cubits above the mountains.

Genesis 7:20 states that the waters prevailed fifteen cubits upward, covering the mountains. The figure appears after the passage describing the rising floodwaters and is part of the narrative’s account of the earth being submerged.

The number is sometimes confused with the ark’s height, which Genesis gives as 30 cubits. Fifteen cubits is half that stated height, but the text uses the number here to describe the depth of water above the mountains, not a measurement of the vessel.

Because ancient cubits varied, converting fifteen cubits into metres is approximate. If one uses a 45-centimetre cubit, the figure would be about 6.75 metres. The passage belongs to the biblical Flood narrative and should not be treated as a modern geological measurement of a worldwide flood.