"Talk about meeting your soul mate," the 42-year-old actress tells Harper's Bazaar in its September issue. "I truly feel I have been given that gift. And believe me, I wasn't some lightweight package. I'm, like, the package that didn't just come with luggage — I had trunks."
While she and Kutcher, 27, would like to "expand our family" — there have been tabloid reports that Moore was pregnant — there are no plans for marriage. "I feel that we are and that we don't need something formal, so to do so isn't a big deal one way or another," she tells the magazine.
"The next phase? The growth of my partnership (with Kutcher). The growth of our union. The growth of our family. Which is all the things we truly desire ... to expand our family."
Moore says the couple, who recently moved into their new home in the Hollywood Hills, enjoy "sharing a bath with one another and watching 'Court TV.' Snuggling up naked."
Moore, who starred in 2003's "Charlie's Angels: Full Throttle," says she met Kutcher "not through Sean Combs, as everyone said, but through a mutual friend, Sara Foster, an actress who's known Ashton from the day he arrived in Los Angeles."
"We met and he said, `I really need to talk to you alone later.' And I was like, 'Heh, yeah, sure.' And he said, `No, no, I'm serious.' And we ended up going back to my apartment and talking all night long."
Moore has three daughters, Rumer, 17; Scout, 14; and Tallulah, 11, from her marriage to second husband Bruce Willis.
She recently finished shooting the thriller "Half Light," appears in a fall ad campaign for Versace and is planning to launch a holistic beauty company with two friends.
"It's been a challenging few years, being the age I am, with so much focus now on how I look," Moore says. "Almost to the point where I felt like, well, they don't know what to do with me. I am flawed. And I'm not 20. Not 30. But I'm certainly different from what most people feel someone in her 40s should be."