Annualized Return Formula

[Arturo Borges]

Hey!

I am trying to find what the formula to calculate the annualized return on an investment is, based on compound interest. So if someone invested $100K and in 4 months it generates a 6% return, that's $6K, if he invested those $106K again, and in another month he'd generated another 6%, what would the total annual return on that initial $100K investment would be?

Thank you very much in advance