According to Genesis, Noah was 600 years old when the Flood began and the Ark voyage started.
Genesis 7:6 gives Noah’s age as 600 when the floodwaters came upon the earth. This detail belongs to the biblical chronology of the Flood story, which also places Noah’s sons, their wives, and Noah’s wife aboard the vessel.
The age is sometimes confused with Noah’s total lifespan. Genesis 9:29 says Noah lived 950 years, so 600 was his age at the Flood, not his age at death. Genesis also gives ages for other patriarchs, creating a long genealogical timeline before the Flood.
The number is a textual detail from Genesis, not a measurement established by archaeology. Different religious traditions may interpret the chronology differently, but the age stated in the Genesis narrative is 600.