Understanding FICO® Scoring

[mmmmmm]

I've always been a bit confused on AAoA and closed tradelines.

For instance, does FICO actually take into account how long your account was open or merely how long it has been reporting.  Does an account that was only open for 1 year and then closed, but has been sitting on your report for 9 years calculate the same as a tradeline that has been open the entire 10 years?

A more specific example: If nI have 2 tradelines and one was closed after a year, and has been sitting on my account for the past 9 years, while the other has been open the entire time, would that make my AAoA 10 years, even though the account was only actually open for 1 year?

Clarification on exactly how it is calculated would be great.

[pizzadude]

Yes, It includes both open and closed accounts. The age of each account is determined based on the date it was opened. Add up the total age in months and divide by 12 to get the years of your AAoA. AAoA rounds down, and FICO® always sets your AAoA to be at least 1 yr.