For many Bible readers, the story of Noah’s ark never gets old. They are in awe when they read about the magnitude of the floodwaters, thankful when imagining how God saved the animals, and hopeful when he chose Noah to build the ark and start a new world with his family. A common question people ask about the flood story is how big the ark was.
The ark God told Noah to build was 300 cubits long, which is 450 feet long or 137.6 meters. It was 50 cubits wide, which is 75 feet or 22.86 meters. And the ark was 30 cubits high, which is 45 feet or 13.71 meters. Most scholars believe the ark had a flat bottom and was rectangular in shape, like a barge.
Where and how does the Bible mention how long, wide, and high the ark was? Could the ark float? Why don’t scholars agree about the nature of its window or roof? Keep reading to learn the answers to these questions and others.
Also see How Long Did It Take Noah To Build the Ark? to learn more.
How long, wide, and tall was Noah’s ark?
After God declared his intention to destroy the world, he commanded Noah to build an ark made of gopher wood, divide the inside of it, and pitch it inside and out (Gen. 6:14).
Next, God told Noah how big the ark needed to be. Though some readers may desire more details about the ark than the flood story provides, as the description falls short of being an actual blueprint, the specifics it offers are remarkable.
What is a cubit? The measurement that the Hebrews used to describe the size of the ark is a cubit. A cubit is a measurement derived from the length of the elbow to the tip of the finger. Some scholars use 50 centimeters as an equivalent to one cubit, yet the Bible doesn’t confirm this assumption.  Instead, 18 inches (45.72 centimeters) is a general guideline from which people can make conversions. 
How do cubits translate to feet? As stated above, most people use 18 inches as the length of a cubit. One way to simplify the conversion is to divide the cubits in half and then multiply that number three times. For example, ten cubits divided in half is 5, and multiplied by three is 15. So ten cubits equal 15 feet (4.57 meters).
What was the length of the ark?
God said the ark would be 300 cubits long. 300 divided in half is 150 and multiplied three times is 450. So the ark was 300 cubits or 450 feet long (137.6 meters).
What was the width of the ark?
God said the ark would be 50 cubits wide. 50 divided in half is 25 and multiplied three times is 75. So 50 cubits equal 75 feet (22.86 meters).
What was the height of the ark?
God said the ark would be 30 cubits high. 30 divided in half is 15 and multiplied three times is 45. So 30 cubits equal 45 feet (13.71 meters).
The size of the ark in English Bible translations
Most popular English translations describe the ark’s measurements in cubits to precisely rendering the Hebrew term. However, the NLT converts cubits into feet for its readers.
|ESV||This is how you are to make it: the length of the ark 300 cubits, its breadth 50 cubits, and its height 30 cubits.|
|KJV||And this is the fashion which thou shalt make it of: The length of the ark shall be three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits.|
|NASB||This is how you shall make it: the length of the ark three hundred cubits, its breadth fifty cubits, and its height thirty cubits.|
|NIV||This is how you are to build it: The ark is to be three hundred cubits long, fifty cubits wide and thirty cubits high.|
|NLT||Make the boat 450 feet long, 75 feet wide, and 45 feet high.|
- The Christian Standard Bible (CSB) also converts cubits for its readers: “This is how you are to make it: The ark will be 450 feet long, 75 feet wide, and 45 feet high.”
- The Amplified Version (AV) adds feet at the end of the verse: “This is the way you are to make it: the length of the ark shall be three hundred cubits, its width fifty cubits, and its height thirty cubits (450’ x 75’ x 45’).”
- The Contemporary English Version (CEV) converts cubits into meters: “Make it 133 meters long, 22 meters wide, and 13 meters high.”
Also see Who Helped Noah Build the Ark? to learn more.
Could the ark float?
Given the measurements that Genesis provides, most scholars think the ark would not only have floated but would have been very difficult to capsize.
Genesis scholar Henry Morris writes, “It can be shown hydrodynamically that a gigantic box of such dimension would be exceedingly stable, almost impossible to capsize. Even in a sea of gigantic waves, the ark could be tilted through any angle up to just short of 90 degrees and would immediately thereafter right itself again.”
He concludes, “Furthermore, it would tend to align itself parallel with the direction of major wave advance and thus be subject to minimum pitching most of the time.” 
Another Genesis scholar Victor Hamilton writes, “The point to be observed here is that the dimensions of Noah’s vessel are completely logical, and what one would expect to find in a seagoing vessel… the size of Noah’s ark possibly suggests that it was large enough and strong enough to weather the Flood, and that it contained enough space to accommodate all the animals.” 
Also see How Long Did Noah Live? to learn more.
Was a roof or window a cubit above the ark?
Genesis scholars disagree about what was on top of the ark, as some think it was a roof and others a window. This is the only place in the Old Testament this particular Hebrew word (tsohar) is used. Major English translations don’t agree on how to render the word.
|ESV||Make a roof for the ark, and finish it to a cubit above, and set the door of the ark in its side. Make it with lower, second, and third decks.|
|KJV||A window shalt thou make to the ark, and in a cubit shalt thou finish it above; and the door of the ark shalt thou set in the side thereof; with lower, second, and third stories shalt thou make it.|
|NASB||You shall make a window for the ark, and finish it to a cubit from the top; and set the door of the ark in the side of it; you shall make it with lower, second, and third decks.|
|NIV||Make a roof for it, leaving below the roof an opening one cubit high all around. Put a door in the side of the ark and make lower, middle and upper decks.|
|NLT||Leave an 18-inch opening below the roof all the way around the boat. Put the door on the side, and build three decks inside the boat—lower, middle, and upper.|
The description of the window or roof being one cubit “above” (ESV) or “from the top” (NASB) of the ark is challenging to understand. One Genesis scholar calls the description, “The most obscure remark in the flood story.” 
Older commentators tend to think it’s a window. New commentators tend to think it’s a roof. Those who think it’s a window associate it with the one Noah opened to release the birds later in the story (Gen. 8:6). However, that verse uses a different Hebrew word for window (challon) and the one used in 6:16.
Those who argue that it’s a roof suggest that the cubit “above” may refer to the length of its overhang.
Also see How Many Animals Were on the Ark? to learn more.
 Genesis 1-11:26 by Kenneth Mathews. p. 364.
 Genesis 1-15 by Gordon Wenham. p. 173.
 The Genesis Record by Henry Morris. p. 180.
 The Book of Genesis: Chapters 1-17 by Victor Hamilton. p. 282.
 Wenham. p. 173.
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