The Oscar winner shared she used to lie about her height during a recent interview with the "Radio Times Podcast" ... admitting she'd shave a half-inch off her stats when casting directors asked.

NK says despite being 5'11" she used to tell CDs she was 5'10" and a half ... not much of a difference, but a lie nonetheless.

The Australian star says people called her "stalky" when she first arrived on the acting scene, and was told a tall woman like her wouldn't have a career.

However, that's changed in recent years with Kidman saying, "Now, I get, ‘You’re so much taller than I thought,' or men grappling with how high my heels should be."

Another interesting anecdote ... NK was nearly turned away from an audition for the musical "Annie" when she was a kid, because she was 2 inches above the 5'2" cutoff line.

Kidman says she's trying to impart courage and resilience to her kids -- she has 2 with Tom Cruise and 2 with Keith Urban -- teaching them how to react when they hear the word "no."