How Long Did It Take for Noah to Build the Ark?

Before investigating whether the Bible says that Noah took 120 years to build the ark, let’s quickly address the second part of the question. We broke ground on May 1, 2014. Most of the first year of construction involved preparing the ground by moving approximately 500,000 cubic yards of dirt from the site and pouring concrete for the foundation, a 50,000-gallon water tank for fire protection, and the towers upon which the Ark rests. The construction of the Ark itself persisted for a little over a year, and we opened to the public on July 7, 2016.

Our construction period only lasted about 26 months, but we had the benefit of modern technologies and hundreds of skilled laborers. Is it possible that Noah’s ark was also built in much less time than many assume? Let’s turn our attention to what God’s Word has to say on this matter.

120 Years?

Why do so many people assume that it took Noah 120 years to build his ark? This idea comes from assumptions drawn from Genesis 6:3, a verse located in the middle of that mysterious and controversial passage about giants (Nephilim) and the sons of God (Genesis 6:1–4). Answers in Genesis does not take an official stance on the identity of the sons of God. For a balanced overview on this subject, see “Battle over the Nephilim.”

The context of Genesis 6:3 has something to do with the sons of God and the Nephilim rather than the construction of the ark.

Genesis 6:3 states, “Then the Lord said, ‘My Spirit shall not abide in man forever, for he is flesh: his days shall be 120 years.’” Like the rest of the verses in this passage, the verse’s meaning is disputed. One view sees the 120 years as a countdown to the flood, and based on that understanding, some people have assumed that this is how much time Noah had to build the ark. However, even if the 120 years should be understood as a countdown to the flood, nothing in this verse or its immediate context says that this is when Noah started building the ark. In fact, the ark is not mentioned until Genesis 6:14, and the flood is first mentioned in Genesis 6:17. So the context of Genesis 6:3 has something to do with the sons of God and the Nephilim rather than the construction of the ark.

100 Years?

Some interpreters have assumed that Noah had 100 years to build the ark. This time period is calculated from the following verses.

After Noah was 500 years old, Noah fathered Shem, Ham, and Japheth. (Genesis 5:32)

Noah was six hundred years old when the flood of waters came upon the earth. (Genesis 7:6)

There was a 100-year period between the time when Noah’s oldest son was born and the flood was unleashed upon the earth. While this is accurate, there is nothing in Scripture to indicate that Noah started building the ark when his oldest son was born.

Maximum of 75 Years?

I believe the Bible provides a couple more hints that allow us to reach a more accurate conclusion than the two views described so far. Immediately after instructing Noah to build the ark and sharing certain details about it, God said, “For behold, I will bring a flood of waters upon the earth to destroy all flesh in which is the breath of life under heaven. Everything that is on the earth shall die. But I will establish my covenant with you, and you shall come into the ark, you, your sons, your wife, and your sons’ wives with you” (Genesis 6:17–18). This passage seems to indicate that Noah’s sons were already married when God told him to build the ark.

If this reasoning is correct, then the amount of time Noah had to build the ark was considerably less than 100 years.

If this reasoning is correct, then the amount of time Noah had to build the ark was considerably less than 100 years (the gap between the birth of his oldest son and the start of the flood). How much less time depends on how long it took for his sons to be born, to grow up, and to get married. It is typical to view Japheth as the oldest son, although Bible translations vary on whether Genesis 10:21 tells us that Shem was the brother of “Japheth the elder” (NKJV, NIV) or whether Shem was “the elder brother of Japheth” (ESV, NET).1 Shem seems to have been born when Noah was 502 or 503, since Genesis 11:10 tells us that Shem was 100 years old when his son Arphaxad was born, and that this occurred two years after the flood. Genesis 9:24 reveals that Ham was Noah’s youngest son, but the text never tells us how much younger he was. For the sake of argument, let’s assume Noah was 505 years old when Ham was born.

Next, we need to know how old the boys were when they married their wives. Since the Bible is silent on this issue as well, we are left to speculate. If we go with a minimum age of 20 years for each of them, this would mean that Noah was approximately 525 years old when his youngest son married. And since the flood began when Noah was 600, this would leave a maximum of 75 years for building the ark.

There is one more detail to consider. The genealogies in Genesis 5 tell us how old the men between Adam and Noah were when their son of record was born. The youngest age listed for any of these men was 65 years old (Mahalelel in Genesis 5:15 and Enoch in Genesis 5:21). Of course, this does not mean they were married when they were 65, but it may indicate that people either matured slower when they lived 900+ years or that for some reason they waited longer to get married. If either of these ideas is correct, then Noah’s sons may have been much older than 20 when they married. If they waited until they were close to 65, then Ham would have married his wife when Noah was about 570 (if our speculation of Ham’s age is accurate). This would leave only about 30 years to build the ark.

Given that there are just too many unknowns related to this topic, it seems best to simply provide a range for the maximum amount of time Noah had to build the ark. Because it seems that Noah’s sons were already married when God gave the command to build the ark and because Noah was likely at least 525 when his youngest son married, then we can tentatively conclude that Noah had about 75 years maximum to build the ark, and it may not have even taken him that long.

Conclusion

While the Bible does not provide all the details we need to give a precise figure for the time Noah had to build the ark, it does give us some parameters that allow us to think that 75 years was roughly the upper limit.

We need to keep one more thing in mind when thinking about this topic. Wood does not last indefinitely in the elements. While we cannot be sure what properties gopher wood possessed, other than being suitable for building the ark, it is reasonable to think that it too would warp and rot like most other types of wood left out in the elements. It is possible that the pitch they used to coat the wood helped prevent this sort of decay.

Rather than repeating the common view that Noah had 120 years to build the ark, it seems more in line with Scripture to think that he had a maximum of about 75 years.

With that in mind, perhaps it did not take Noah as long as many imagine. Is there any reason he could not have accomplished this feat in 20–25 years? Sure, he may not have had all the modern equipment we used and his work crews may have been smaller than what we had to build our ark in just over two years, but is it really impossible to imagine that this godly man built the ark in far less time than is typically assumed?

Rather than repeating the common view that Noah had 120 years to build the ark, it seems more in line with Scripture to think that he had a maximum of about 75 years.