At what age does Genesis say Noah became the father of Shem, Ham, and Japheth?

Genesis says Noah was 500 years old when he became the father of Shem, Ham, and Japheth.

Genesis 5:32 gives Noah’s age as 500 when it introduces his three sons. The passage does not necessarily mean that all three were born on the same day or that their birth order is stated there. Elsewhere, the biblical chronology provides additional age references that readers use when reconstructing the sequence of events.

Genesis 7:6 says Noah was 600 years old when the Flood came. That ten-decade interval is one reason the ages in the narrative are often remembered together. Genesis later says Noah lived 350 years after the Flood and died at 950.

The sons’ names are important because they become the ancestors of the post-Flood nations in the story’s genealogy. The question concerns Noah’s age at the introduction of his sons, not his age when he entered the Ark or when the Flood began.