Kirstie Alley:

The pounds keep melting away!

Kirstie Alley -- who's competing on this season of Dancing With the Stars -- tells Us Weekly that dancing "every day" has helped her drop several dress sizes.

"I started out in a size 12, then an 8, and then I think next week I'll be in a 6," she said after her performance Monday night. "The real size I want to be in is probably a 4 or a 6. That's where I look best."

The 60-year-old actress -- who will debut her Organic Liaison weight loss system on QVC Saturday at 11 a.m. EST  -- hinted that she may even do a big weight loss reveal on Oprah.

"There aren't that many Oprah shows left, but you never know," she teased. "It's whittling fast, and I'm dancing every day. Who knows?"