How long did it take Noah to build the ark?

Genesis never gives a single verse stating how many years the ark took to build, but the surrounding chronology allows a reasonable estimate. Genesis 5:32 records that Noah was 500 years old when his sons Shem, Ham, and Japheth were born. Genesis 6:1-3 and the genealogies suggest God's judgment and the command to build the ark came sometime after this. Genesis 7:6 then states plainly that "Noah was six hundred years old when the flood of waters was upon the earth." That leaves a window of up to 100 years between Noah's sons being born and the flood arriving, during which the ark was built, gathered materials, and the family prepared - though the actual building period was likely somewhat shorter, since Genesis 6:10 says his sons were already grown men (able to marry and have wives, Genesis 7:13) by the time the flood came. Most conservative estimates place the actual construction period between 55 and 75 years, an immense undertaking reflecting both the ark's massive size (about 450 feet long per Genesis 6:15) and Noah's patient obedience while, as 2 Peter 2:5 notes, he served as "a preacher of righteousness" during that time.

Key Passages