The son of a professional gambler, he was of Irish ancestry. He was only nine months old when his father died; Calhoun's mother remarried, and he occasionally went by Frank Durgin, using the last name of his stepfather.
At age thirteen, he stole a revolver, for which he was sent to the California Youth Authority's Preston School of Industry reformatory at Ione, California. He escaped while in the adjustment center (jail within the jail). After robbing several jewelry stores, he stole a car and drove it across state lines. This made it a federal offense, and when he was recaptured, he was sentenced to three years in prison. He served his sentence at the United States Medical Center for Federal Prisoners in Springfield, Missouri. He remained there until he was paroled shortly before his twenty-first birthday.
Calhoun worked at a number of odd jobs. In 1943, while riding horseback in the Hollywood Hills, he met actor Alan Ladd, whose wife, Sue Carol was an agent. She landed Calhoun a one-line role in a Laurel and Hardy comedy, The Bullfighters, credited under the name Frank McCown. Shortly afterwards, the Ladds hosted a party attended by David O. Selznick employee Henry Willson, an agent known for his assortment of young, handsome and marginally talented actors.
Calhoun appeared in 'Adventure Island' with Rhonda Fleming, 'The Red House' with Edward G. Robinson, and 'That Hagen Girl' with Shirley Temple.
As Calhoun's career gained momentum, he next appeared in several westerns, musicals and comedies, including Way of a Gaucho with Gene Tierney, 'With a Song in My Heart' with Susan Hayward, 'How to Marry a Millionaire' (as the love interest of Betty Grable) and 'River of No Return'. The last two films featured Marilyn Monroe. Calhoun also made a variety of films in Europe, notably starring in Sergio Leone's first film, 'The Colossus of Rhodes'.
He was married twice. He had five daughters, three with first wife Lita Baron (m. 1948-1970), Cindy, Tami and Lori, one with actress Vitina Marcus, and one with his second wife journalist Sue Rhodes. When Lita Baron sued Calhoun for divorce, she named Betty Grable as one of 79 women with whom he had adulterous relationships. Calhoun replied to her charge, "Heck, she didn't even include half of them".
In 1966, Vitina Marcus filed a paternity suit against Calhoun. Both actors were married at the time. The suit was settled in Los Angeles Superior Court for an undisclosed sum.
He died in Burbank, California, at the age of 76 from complications resulting from emphysema and diabetes.
