In Genesis, what length does God specify for Noah’s Ark?

In Genesis, God specifies that Noah’s Ark should be 300 cubits long.

The measurement appears in Genesis 6:15, alongside the Ark’s width of 50 cubits and height of 30 cubits. A cubit was an ancient unit based approximately on the length of a forearm, so its exact modern equivalent is uncertain. Using commonly suggested values, 300 cubits would be roughly 135 to 157 metres.

These dimensions describe the Ark as a long, box-like vessel rather than a conventional ship designed for sailing. Genesis emphasizes its construction, internal compartments, waterproofing, and capacity, but does not provide a detailed naval design or identify the precise type of wood in modern botanical terms.

The length is often confused with the Ark’s width or height because all three measurements are given together. The same basic dimensions are also discussed in later Jewish, Christian, and Islamic traditions, although those traditions do not always preserve every construction detail in the same way.