The cut of roast beef determines the cooking time per pound. In a 325-degree Fahrenheit oven, a bone-in rib roast requires 23 to 30 minutes for each pound, while the boneless version needs 39 to 43 minutes.
An eye round roast must be in the oven for 20 to 22 minutes per pound. A 4- to 6-pound whole tenderloin roast cooks 45 to 60 minutes total. A 2- to 3-pound tenderloin roast needs only about 35 to 45 minutes in all.
You should cook any roast beef to a minimum internal temperature of 145 degrees Fahrenheit. Once the roast comes out of the oven, it should rest for at least 3 minutes before you carve it.