How long was Noah’s ark according to the measurements in Genesis?

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

Genesis 6:15 gives the ark’s dimensions as 300 cubits in length, 50 cubits in width, and 30 cubits in height. A cubit was an ancient unit based broadly on the length of a forearm, so its exact modern equivalent varies. Using common estimates, 300 cubits is often rendered as roughly 135 to 150 meters, but the biblical text itself gives the measurement only in cubits.

The proportions are approximately six to one in length versus width and ten to one in length versus height. Modern ship designers sometimes note that such proportions would resemble a large, stable barge, although that observation does not prove the story’s historicity.

The number 300 refers to length, not the ark’s total dimensions or capacity. The same verse supplies the other two measurements, which are frequently mixed up in simplified retellings.