I am wearing a 2 Petite in this blazer. I tried a 0 Regular initially, but the fit was off - it was too long in the body. The petite is a much better fit!! This is a classic wardrobe staple that you can style so many ways - definitely a great investment for the long haul. Jeans a from last year at JCrew Factory but linked this years version which looks the same. I wear a 25 in their denim which is consistent with other brands for me