Cooking a turkey in an oven bag generally takes between two and a half to three and a half hours. The cooking time depends largely on the size of the turkey.
Many factors that affect the cooking time of a turkey in an oven bag, the most important of which is the size of the bird. The larger the turkey, the longer the cook time must be. To ensure food safety, the U.S. Department of Agriculture recommends that cooking a turkey at an oven temperature of 325 degrees Fahrenheit or higher, and that the turkey's internal temperature reaches at least 165 degrees Fahrenheit. Before removing a turkey from the oven, the minimum internal temperature should always be checked.