How old was Hilary Duff in Cheaper by the Dozen?

It's common to wonder how old a celebrity was when they starred in a particular film. Knowing that can offer insight into their career stage and personal growth. Here’s the answer to that particular curiosity.

Hilary Duff was this age when he appeared in Cheaper by the Dozen:

15 years old

According to our findings, that was the correct age of the celebrity.

This age was calculated based on the beginning of the release year of Cheaper by the Dozen:

January 1, 2003

And the date of birth of Hilary Duff:

September 28, 1987

As films generally take less than a year from filming to release, the age of Hilary Duff during production could differ by a year from what’s shown.