Most people are familiar with the story of Noah’s Ark, but how long did it take Noah to build it?

“So make for yourself an ark of cypress wood; make rooms in it and coat it with pitch inside and out. This is how you are to build it: The ark is to be three hundred cubits long, fifty cubits wide, and thirty cubits high. 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” (Genesis 6:14-16, NIV).

A “cubit” was equal to eighteen inches in modern measurements. That means that the ark was 450 feet long, 75 feet wide, and 45 feet high. That’s big! For comparison, the Titanic was about 900 feet long, 92 feet wide, and 175 feet high (although its height included the funnels, or chimneys, for its boilers). So, for Noah to build his ark by hand – made of wood and coated with pitch – was a huge task!

How Long Did it Take Noah to Build the Ark?

The Bible does not give us a direct answer to the question, “How long did it take Noah to build the ark?” However, some clues can help us understand. First, we have the modern example of the “Ark Encounter.” This organization built a replica of the ark with the same dimensions as Noah’s ark, although the interior of the ark is different. According to the Ark Encounter website, it took them about six years to build their replica of Noah’s Ark.

Of course, Noah needed modern tools or construction procedures to help him. He also had a small crew of workers! Thus, it’s clear that it took Noah much longer than six years to build the ark.

Scriptural Evidence: Genesis

Our next clues come from Scripture. Genesis 5:32 reads, “After Noah was 500 years old, he became the father of Shem, Ham and Japheth.” In Genesis 6:18, God tells Noah that after he has built the ark, he and his wife and their sons and their wives are to enter the ark. Finally, Genesis 7:6 says that Noah was 600 years old when the flood began. This tells us that it must have taken Noah less than 100 years to build the ark because his sons already had wives when God commanded him to build it. If all three of Noah’s sons were born by the time Noah was 500 years old, then we would still need time for them to mature and get married. In fact, the time frame could have been shorter; if Genesis 5:32 means that Noah began having sons at the age of 500, it would have taken at least a few more years for the three of them to be born.

One other factor to consider is that Genesis 5 gives us the genealogy of Adam’s descendants up to Noah. All of Adam’s descendants, other than Noah, had their first sons between the ages of 65 (Mahalalel and Enoch) and 187 (Methuselah). It seems strange that Noah would not have his first son until the age of 500, given his family history. Therefore, it is more likely that he had all three of his sons by the time he was 500 years old.

Scriptural Evidence: New Testament

Three New Testament passages provide additional circumstantial evidence to consider. First, in Matthew 24, Jesus compares the days of his return with the days of Noah: “For in the days before the flood, people were eating and drinking, marrying and giving in marriage, up to the day Noah entered the ark; and they knew nothing about what would happen until the flood came and took them all away” (Matthew 24:38-39). This gives the impression that there was a period during which Noah was building the ark, and the people around him carried on with their lives with no thought about what was to come. In other words, the process was long enough that the flood didn’t “sneak up on them.”

Next, 1 Peter 3:20 refers to Noah’s construction of the ark. He talks about Jesus preaching to the “imprisoned spirits”: “to those who were disobedient long ago when God waited patiently in the days of Noah while the ark was being built.” The phrase “God waited patiently” implies that the process of building the ark took a great deal of time. Finally, Hebrews 11:7-8 picks up this theme in commending Noah for his example to those around him. “By faith, Noah, when warned about things not yet seen, in holy fear, built an ark to save his family. By his faith, he condemned the world and became heir to the righteousness that is in keeping with faith.”

These New Testament passages give the impression that it took Noah quite some time to build build the ark and that his work served as “preaching” to those around him. The length of time that Noah took to build the ark gave ample opportunity for people to repent – and made clear that God’s judgment against them was warranted.

The Process of Building the Ark

What steps would Noah have taken to build the ark? First, God gave him the “blueprints.” Genesis 6:14-16 set forth the dimensions and the basic design, but God must have given Noah more specific directions. After all, Noah had never built a boat before! In fact, it’s not clear that Noah had ever seen a boat! Second, God would also have had to teach Noah how to build the ark. Cutting trees, joining boards together, building stairs between the decks and coating the entire ark with pitch inside and out – these are just a few of the things that Noah needed to learn how to do.

Third, consider the sheer magnitude of the job. How long would it have taken Noah to coat the inside and outside of the ark with pitch after the ark was built? Think of painting something 450 feet long, 75 feet high, and 45 feet wide. On top of that, Noah would have to collect the pitch and bring it to the ark. After the huge job of building the ark, he still faced the challenge of coating it all with pitch, inside and out! And, of course, as noted earlier, he didn’t have a work crew to rely on; at most, he had his wife, his sons and their wives.

How Long Did it Take Noah to Build the Ark?

It’s impossible to say with certainty how long it took Noah to build the ark. However, it seems reasonable to conclude that it took him at least 50 years and maybe as much as 75 years. Such a period would give him time to learn how to build such a structure, gather materials, and complete the project. Remember that he also needed to attend to the “normal business of life.” Given the magnitude of the project, his other responsibilities, and the unfamiliarity of it all, it’s not surprising that the job would take that long!