How Long Do You Cook Pork Loin in the Oven?
Cook boneless pork loin in the oven at 350 F, with 26 to 28 minutes allotted for a roast smaller than 2 pounds and 20 to 25 minutes allotted for a roast that is 3 to 5 pounds. The final internal temperature should be at least 145 F.
For example, a boneless roast that is 4 pounds would be ready to serve after one hour and 20 minutes to one hour and 40 minutes in a 350 F oven. For a slightly more well-done roast, leave it in the oven a bit longer, up to an internal temperature of 165 F.