"It was the prospect of having a kid, and I knew that in nine months there's gonna be a baby here," Hanks told ET's Katie Krause on Tuesday. "That gave me the motivation to be like, 'OK, I've had my time now, and I need to move on."
The 27-year-old performer, who is the eldest son of Tom Hanks and Rita Wilson, admitted that he "had known for a while" that he needed to get sober, but explained how, in the throes of addiction, "You just don't really wanna make the change yet. You don't really want to do the work."
"There's a part of you that knows that you need to make a change but you can't really shut that door on your life and just move on to a new chapter," he reflected. "For me, it took something drastic happening, like becoming a father, for me to make the change."
Hanks reportedly welcomed his daughter, Michaiah, in April 2016, with girlfriend Tiffany Miles.
While sitting down with ET, Hanks was joined by bandmate Drew Arthur. Together, they make up the music duo FTRZ, and they dished on the deeper meaning behind their recently released first single, "Models."
"The opening lyric of the song is, 'From the bottom of the bottle to touching California models,' and it goes on to just talk about how we changed our lives from basically a path of heavy substance abuse -- drugs, alcohol, partying, that kind of whole lifestyle -- to being better men," Hanks explained.
And he says it was his strong desire for bettering his life that first made him realize he wasn't interested in "settling for this mediocre existence," and that he needed to "make a drastic change, completely flip the script, to get what I want out of life."
"They couldn't be more supportive," he shared. "Every step of the way… They've always been there for me and I'm really lucky."
He said they also really "love being grandparents."
"It's awesome seeing them being grandparents as well, because I was really close with my grandparents and now my daughter gets to have the same experience," Hanks shared, adding that they offer to babysit his little girl "all the time."
As for his work with FTRZ, the duo are set to release their first album, The Ocean Park EP, on Aug. 24, and the artists said they also hope that the honesty and message of their music can help other people struggling with the same issues they've faced.
"I feel a responsibility like to tell the truth… and be as open as possible, because there is such a bad drug epidemic going on," Hanks said, "It's a bad problem and I feel like there should be no stigma around people who get sober, because you need to be open to help other people."
"If you just get sober and try to keep it a secret, you're not really helping anybody because there could be somebody that's struggling really hard and if you can be an inspiration to that person to make the change for them to change their life, you can't put a price on that," he added. "
Hanks solemnly admitted that he "could easily be dead or in jail right now" if he hadn't put in the work to change his life, and added "if us, just sharing our story, can be the spark for somebody else to make that decision in their life, and leave the past behind and open up a new chapter in their life, that is the most rewarding and most fulfilling thing. It's the best part about doing music in the first place."
NEW YORK, NY - APRIL 26: Rita Wilson and Tom Hanks attend the premiere of 'The Circle' during the 2017 Tribeca Film Festival at Borough of Manhattan Community College on April 26, 2017 in New York City. (Photo by Taylor Hill/Getty Images)
BEVERLY HILLS, CA - FEBRUARY 16: Actress Rita Wilson and actor Tom Hanks attend An Unforgettable Evening at the Beverly Wilshire Four Seasons Hotel on February 16, 2017 in Beverly Hills, California. (Photo by Jason LaVeris/FilmMagic)
Tom Hanks and Rita Wilson attend the EE British Academy Film Awards 2014 at The Royal Opera House on February 16, 2014 in London, England. (Photo by Anthony Harvey/Getty Images)
Tom Hanks and Rita Wilson walk the red carpet during the 27th Annual Kennedy Center Honors at John F. Kennedy Center for the Performing Arts on December 7, 2014 in Washington, DC. (Photo by Kris Connor/Getty Images)
Tom Hanks (L) and Rita Wilson host the National Park Foundation and Google's 'Made with Code' National Christmas Tree Lightening Ceremony on December 4, 2014 in Washington, DC. (Photo by Larry French/Getty Images for Google)
Tom Hanks and Rita Wilson attend the EE British Academy Film Awards 2014 at The Royal Opera House on February 16, 2014 in London, England. (Photo by Tim P. Whitby/Getty Images)
Rita Wilson (C) attends the cinema prive And PANDORA Jewelry Host A Special Screening Of 'Cake' on November 23, 2014 in West Hollywood, California. (Photo by Araya Diaz/Getty Images for cinema prive)
LOS ANGELES, CA - JANUARY 12: Actors Tom Hanks (L) and Rita Wilson attend HBO's Post 2014 Golden Globe Awards Party at Circa 55 Restaurant on January 12, 2014 in Los Angeles, California. (Photo by Mike Windle/Getty Images)
Actor Tom Hanks and his wife Rita Wilson (R) react while taking questions from the television media following their arrival for the US Premiere of the film 'Saving Mr. Banks' at the Walt Disney Studios in Burbank, California, on December 9, 2013. The film has a limited opening on December 13 and will open nationwide on December 20. AFP PHOTO / Frederic J. Brown (Photo credit should read FREDERIC J. BROWN/AFP/Getty Images)
SANTA MONICA, CA - SEPTEMBER 25: Actress Rita Wilson (L) and husband actor Tom Hanks arrive at the 23rd Annual Simply Shakespeare Benefit reading of 'The Two Gentleman of Verona' at The Broad Stage on September 25, 2013 in Santa Monica, California. (Photo by Kevin Winter/Getty Images)
NEW YORK, NY - JUNE 09: Actors Tom Hanks and Rita Wilson attend The 67th Annual Tony Awards at Radio City Music Hall on June 9, 2013 in New York City. (Photo by Neilson Barnard/Getty Images)
PHOENIX, AZ - MARCH 23: Actress Rita Wilson attends Muhammad Ali's Celebrity Fight Night XIX at JW Marriott Desert Ridge Resort & Spa on March 23, 2013 in Phoenix, Arizona. (Photo by Michael Buckner/Getty Images for Fight Night)
LOS ANGELES, CA - FEBRUARY 08: Actress Rita Wilson arrives at he 2013 MusiCares Person Of The Year Gala Honoring Bruce Springsteen at Los Angeles Convention Center on February 8, 2013 in Los Angeles, California. (Photo by Jason Kempin/Getty Images)
Actor Tom Hanks and Rita Wilson arrive at Warner Bros. Pictures' 'Cloud Atlas' premiere at Grauman's Chinese Theatre on October 24, 2012 in Hollywood, California. AFP PHOTO/JOE KLAMAR (Photo credit should read JOE KLAMAR/AFP/Getty Images)
WEST HOLLYWOOD, CA - MAY 04: Actress/singer Rita Wilson performs at The Troubadour on May 4, 2012 in West Hollywood, California. (Photo by Kevin Winter/Getty Images)
Rita Wilson performs on stage at Muhammad Ali's Celebrity Fight Night XVIII on March 24, 2012 in Phoenix, Arizona. The event supports the fight against Parkinson's disease and this year also celebrates Ali's 70th birthday. AFP PHOTO / Robyn BECK (Photo credit should read ROBYN BECK/AFP/Getty Images)
PHOENIX, AZ - MARCH 24: Actors Rita Wilson (L) and Tom Hanks attend Muhammad Ali's Celebrity Fight Night XVIII held at JW Marriott Desert Ridge Resort & Spa on March 24, 2012 in Phoenix, Arizona. (Photo by Michael Buckner/Getty Images for CFN)
HOLLYWOOD, CA - JUNE 27: Actress Rita WIlson arrives at the Premiere of Universal Pictures' 'Larry Crowne' at Grauman's Chinese Theatre on June 27, 2011 in Hollywood, California. (Photo by Jason Merritt/Getty Images)
WESTWOOD, CA - MAY 09: Actor Tom Hanks (L) and actress Rita Wilson attend The Shakespeare Center of Los Angeles' 21st Annual 'Simply Shakespeare' performance at Royce Hall, UCLA on May 9, 2011 in Westwood, California. (Photo by Frederick M. Brown/Getty Images)
WEST HOLLYWOOD, CA - FEBRUARY 27: Actors Tom Hanks and Rita Wilson arrive at the Vanity Fair Oscar party hosted by Graydon Carter held at Sunset Tower on February 27, 2011 in West Hollywood, California. (Photo by Pascal Le Segretain/Getty Images)
US actor, director, and producer Tom Hanks arrives with his wife Rita Wilson for the World Premiere of his latest film Mamma Mia in London's Leicester Square, on June 30, 2008. AFP Photo/Max Nash (Photo credit should read MAX NASH/AFP/Getty Images)
HOLLYWOOD - NOVEMBER 10: Actress Rita Wilson arrives at the World Premiere of 'Beautiful Ohio' during AFI FEST 2006 presented by Audi held at the LOFT at Arclight Hollywood on November 10, 2006 in Hollywood, California. (Photo by Michael Buckner/Getty Images)
BEVERLY HILLS, CA - SEPTEMBER 29: Actors Tom Hanks and Rita Wilson arrive at the Sony Global Marketing Partners' Conference Closing Celebration held on Rodeo Drive on September 29,2006 in Beverly Hills, California. (Photo by Frazer Harrison/Getty Images)
CANNES, FRANCE - MAY 17: Actors Rita Wilson and Tom Hanks, attend 'The Da Vinci Code' World Premiere & Opening Gala at the Palais during the 59th International Cannes Film Festival May 17, 2006 in Cannes, France. (Photo by Gareth Cattermole/Getty Images)
BEVERLY HILLS, CA - MARCH 1: Actor Tom Hanks and actress Rita Wilson speak during the EIF's Women's Cancer Research Fund honoring Melissa Etheridge at Saks Fifth Avenue's Unforgettable Evening on March 1, 2006 at the Regent Beverly Wilshire Hotel in Beverly Hills, California. (Photo by Kevin Winter/Getty Images)
BEVERLY HILLS, CA - OCTOBER 15: Actor Tom Hanks and wife Rita Wilson attend the 2005 Saint John's Health Center Gala Caritas Award, where Tom Hanks and Rita Wilson were honored, at the Beverly Wilshire Hotel on October 15, 2005 in Beverly Hills, California. (Photo by Frazer Harrison/Getty Images)
PARK CITY, UT - JANUARY 27: Actress Rita Wilson poses for portraits during the 2005 Sundance Film Festival January 27, 2005 in Park City, Utah. (Photo by Carlo Allegri/Getty Images)
CANNES, FRANCE - MAY 18: Actors Tom Hanks and wife Rita Wilson attend the screening of the film 'The Ladykillers' at the Palais des Festivals during the 57th International Cannes Film Festival May 18, 2004 in Cannes, France. (Photo by Pascal Le Segretain/Getty Images)
HOLLYWOOD - MARCH 12: Actor Tom Hanks (R) and actress Rita Wilson (L) arrive for the world premiere of the movie 'Ladykillers' at the El Capitan Theatre March 12, 2004 in Hollywood, CA. The movie goes into wide release on March 26th, 2004. (Photo by Carlo Allegri/Getty Images)
LOS ANGELES - OCTOBER 25: (TABLOIDS OUT) (L-R) Actress Rita Wilson and actor husband Tom Hanks at the Walt Disney Concert Hall opening gala after party, day three of three, October 25, 2003 in Los Angeles, California. Tonight, 'Soundstage LA: An Inaugural Gala for Walt Disney Concert Hall,' celebrates Hollywood as a creative state of mind. (Photo by Carlo Allegri/Getty Images for LAPA)
LOS ANGELES - MARCH 2: Producer Rita Wilson hugs husband actor Tom Hanks during the 14th Annual Producers Guild Awards at the Century Plaza Hotel on March 2, 2003 in Los Angeles, California. (Photo by Vince Bucci/Getty Images)