The surprising real ages of actors when they were cast to play famous teenage roles

Blaque bring it onUniversal PicturesGabrielle Union (center) was not a teen when she starred in ‘Bring It On.’

Age is but a number, and you don’t have to be a teenager to play one on TV or film.

While some actors are closer in age to their character counterparts, others can be two or even 15 years older than the characters they portray.

Here are 11 celebrities who are well-known for their teen roles, even though they weren’t teens at the time.

Troian Bellisario plays Spencer Hastings on 'Pretty Little Liars,' an 18-year-old high school student.

Warner Bros./ABC Family/screenshot
Troian Bellisario as Spencer Hastings in the series premiere of 'Pretty Little Liars.'

In real life, Bellisario is 29. She was 24 when she was cast as the high school junior. The characters graduated in the mid-season finale, and when the series returns in January, it's jumping ahead five years.

Ben Gabbe/Getty Images)
NEW YORK, NY - OCTOBER 11: Actress Troian Bellisario attends PaleyFest New York 2015 for 'Pretty Little Liars' at The Paley Center for Media on October 11, 2015 in New York City.

(Als0 0f note: Sasha Pieterse, who plays Alison DiLaurentis, is 19, so when the show returns, she'll be playing an older character.)

Minka Kelly played high school cheerleader Lyla Garrity in 'Friday Night Lights.'

NBCUniversal
Minka Kelly as Lyla Garrity in 'Friday Night Lights.'

She was 26 when the show premiered and was 28 when her character finally graduated from high school and headed off to Vanderbilt University. Current age: 35

Jason Kempin/Getty Images
Minka Kelly attends the Vanity Fair And Juicy Couture Celebration Of The 2013 Vanities Calendar With Olivia Munn at Chateau Marmont on February 18, 2013 in Los Angeles.

Rachel McAdams ruled the Plastics as high school queen bee, Regina George, in 'Mean Girls.'

Rachel McAdams as Regina George.

She was 25 when she was cast. Current age: 36

Alberto E. Rodriguez/Getty Images
TORONTO, ON - SEPTEMBER 14: Actress Rachel McAdams attends the 'Spotlight' premiere during the 2015 Toronto International Film Festival at the Princess of Wales Theatre on September 14, 2015 in Toronto, Canada.

Gabrielle Union played a sophomore high school student and best friend to Bianca Stratford in '10 Things I Hate About You.'

Buena Vista Pictures/screencap
Gabrielle Union and Larisa Oleynik in '10 Things I Hate About You.'

She was 26 when the film was released, while Larisa Oleynik (Bianca) was 18.

Ben Gabbe/Getty Images
NEW YORK, NY - SEPTEMBER 14: Actress Gabrielle Union attends the rag & bone Spring 2016 fashion show during New York Fashion Week at St. Ann's Warehouse on September 14, 2015 in New York City.

The following year, she appeared in another high school role as the head cheerleader of the East Compton Clovers in 'Bring it On.' Current age: 42

Universal Pictures
Gabrielle Union in 'Bring it On.'

Cam Gigandet portrayed Micah, a 20-year-old Christian high school student who contracts chlamydia, in 'Easy A.'

Screen Gems/screenshot
Cam Gigandet in 'Easy A'

Gigandet was 27 during filming. Because of his real age, there is an age joke incorporated into the film where Olive (Emma Stone) asks what a '22-year-old' is still doing in high school. Current age: 33

Ian Gavan/Getty Images
:LONDON, ENGLAND - DECEMBER 13: Actor Cam Gigandet attends the UK premiere of 'Burlesque' at Empire Cinema, Leicester Square on December 13, 2010 in London, England.

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Chad Michael Murray won the hearts of teen girls everywhere as Lucas, a brooding basketball player with a penchant for writing, in 'One Tree Hill.'

Warner Bros./screencap
Chad Michael Murray in 'One Tree Hill.'

Though Lucas was supposed be 16 in the first season, Murray was 22 when the show premiered and 26 when his character graduated from high school. In season 5, the timeline jumped ahead four years. Current age: 34

Bryan Bedder/Getty Images for Sony Pictures Television
NEW YORK, NY - APRIL 30: Actor Chad Michael Murray attends the Crackle NewFronts at Cedar Lake Studios on April 30, 2014 in New York City.

Ferris' day off could not be complete without his best friend Cameron, played by Alan Ruck, in 'Ferris Bueller's Day Off.'

Paramount Pictures/screencap
Alan Ruck in 'Ferris Bueller's Day Off.'

Ruck was 29 when he played Cameron. In comparison, Matthew Broderick (Ferris) was 23 and Mia Sara (Sloane) was 18. Current age: 59

Dave Kotinsky/Getty Images
NEW YORK, NY - JUNE 17: Alan Ruck attends 'World War Z' New York Premiere on June 17, 2013 in New York City.

Benjamin McKenzie's Ryan Atwood was the bad boy with a big heart, whose arrival rocked Newport Beach, in 'The O.C.'

Warner Bros./screencap
Benjamin McKenzie in 'The O.C.'

McKenzie was 25 when he landed the role and 28 when Ryan finished high school. Current age: 37

Laura Cavanaugh/Getty Images
NEW YORK, NY - OCTOBER 11: Benjamin McKenzie of 'Gotham' attends New York Comic Con 2015 - Day 4 at The Jacob K. Javits Convention Center on October 11, 2015 in New York City.

Stockard Channing earned a People's Choice Award for her role as high school student, Rizzo, in the musical 'Grease.'

Paramount Pictures/screenshot
Stockard Channing in 'Grease.'

She was 33 when she was cast in the role. (Much of the cast was older than their high school counterparts. For example, Olivia Newton-John was turning 30 when she cast.) Current age: 71

Jenny Anderson/Getty Images for the McKittrick Hotel
NEW YORK, NY - MARCH 03: Stockard Channing attends 'Six Degrees Of Stockard Channing' at The Lodge at The McKittrick Hotel on March 3, 2015 in New York City.

Jason Earles is best known as Miley's goofy older brother on Disney's 'Hannah Montana.'

Disney Channel/screenshot
Jason Earles in 'Hannah Montana.'

But though he was portraying a 16-year-old high school student, Earles was 29.

Mark Davis/Getty Images
LOS ANGELES, CA - JUNE 03: Jason Earles attends the 'Summer With Cimorelli' red carpet premiere event at YouTube Space LA on June 3, 2014 in Los Angeles, California.

Stacey Dash is well-known as Cher's best friend in the cult comedy 'Clueless.'

Dash was 28 during the filming of the movie, ten years older than Alicia Silverstone (Cher). Current age: 48

Rob Kim/Getty Images
NEW YORK, NY - DECEMBER 15: Stacey Dash arrives at the 'American Sniper' New York Premiere at Frederick P. Rose Hall, Jazz at Lincoln Center on December 15, 2014 in New York City.

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