How much does a domain’s age affect its ranking?

Domain age. “How much weight does the number of years a domain is registered for have on your ranking?” May 2009

Short answer is not to worry very much about it. Some say that Google give a bonus in ranking if your site has been registered for three or more years.

This is not based on anything that Google has said. It is true that Google filed a patent based on historical data but it has never put it to use in determining positioning.

Matt Cutts 2009

Also

live q&a september 21, 2011

@18 mins

Fresh information helps.

Having an older website does not mean that you automatically get a ranking boost.

If a website has been around for a while it should have picked up links and that can lead to the confusion that age alone helps.