But the design is so classic that it's super easy to find without resorting to dropping major cash for the Tom Ford original!
We found two equally affordable options that are super similar to Kate's dress.
Check 'em out ...AFTER THE JUMP!!!
She's growing up before our very eyes!
Going all-out for her big day, the actress wore a beautiful powder blue Chanel Resort A-line dress with floral embellished belt, which she paired with a faux leather Aeropostale jacket.
AWESOME mix of high-low! Anna Wintour would be proud!
Chloë also added a beige Chanel quilted shoulder bag and two-tone suede pumps to the ensemble.
Ugh, she's just so stylish already! Whatever happened to that awkward stage every teen's supposed to go through?!
Oh well, happy birthday, girl!
[Image via C. Smith/WENN.]