LogFAQs > #932556994

I call it both.

https://en.wikipedia.org/wiki/Jacket
A jacket is a mid-stomachlength garment for the upper body. A jacket typically has sleeves, and fastens in the front or slightly on the side. A jacket is generally lighter, tighter-fitting, and less insulating than a coat, which is outerwear. Some jackets are fashionable, while others serve as protective clothing.

https://en.wikipedia.org/wiki/Coat
A coat is a garment worn on the upper body by either sex, for warmth or fashion. Coats typically have long sleeves and are open down the front, closing by means of buttons, zippers, hook-and-loop fasteners, toggles, a belt, or a combination of some of these.