How old was macaulay culkin when he did his 3rd home alone movie?

Macaulay Culkin was 14 years old when he filmed "Home Alone 3".

While he did appear in the "Home Alone" franchise, he was not in the third installment. The main character, Alex Pruitt, was played by Alex D. Linz. Macaulay Culkin did not return to the franchise after "Home Alone 2: Lost in New York".