Cooked separately, chicken and potatoes have different baking times. Most recipes specify 375 Fahrenheit for the majority of the chicken’s cooking process to avoid drying out the bird. Recipes for baked or roasted potatoes, on the other hand, often call for an oven temperature of 400 Fahrenheit. If you bake chicken and potatoes together, calculate the ultimate cooking times of each at the lower of the specified temperatures to determine when to add the potatoes.

How long your chicken will take to cook depends on its size and whether it is stuffed, notes the USDA’s Food Safety and Inspection Service. A 3 to 4 lb. chicken, unstuffed, will take between 1 ¼ to 1 ½ hours, while a stuffed bird of the same weight cooks between 1 ½ to 2 hours. Unstuffed chickens in the 5 to 8 lb. range requires between 2 to 3 hours, with an additional 15 or 30 minutes needed when the chicken is stuffed.

As with chicken, the size and type of potatoes you use determines the cooking time. Whole large baked potatoes, when cooked alone, can be baked in 1 to 1 ½ hours at 400 degrees Fahrenheit. But because that temperature would dry out the chicken, count on at least 1 ½ hours to bake whole potatoes at 375 degrees Fahrenheit. Small, whole spuds such as the red, “new” potatoes bake in about 50 to 60 minutes, while cubed or quartered potatoes cook much more quickly. If you cook them with chicken, assume they will take about 30 to 40 minutes at 375 degrees.

Thaw frozen chicken or bring refrigerated chicken to room temperature and preheat the oven to 375 degrees. Season according to your recipe, and place the bird on a roasting rack fitted into a roasting pan. Place the chicken in the oven and set the timer for the total baking time of the chicken, minus the baking time of the potatoes. For example, if the chicken will be done in 90 minutes and the potatoes in 40 minutes, set the timer for 50 minutes. As the chicken bakes, prepare your potatoes. Scrub whole potatoes and poke several holes in their skins with a fork to allow skin to escape. Alternatively, quarter large potatoes or halve small potatoes after scrubbing them. If desired, lightly crush whole or cut potatoes with olive oil. When the timer sounds, remove the pan from the oven, lift out the roasting rack and careful pour the chicken fat from the bottom of the pan. Return the chicken to the pan, without the roasting rack, and surround it with the whole or cut potatoes. Set the timer for the estimated remaining roasting time for the chicken, which is the total cooking time for the potatoes. When the timer sounds, check to see if the potatoes are fork-tender and if the juices run clear when the legs of the chicken are pierced.

Your recipe may specify starting the chicken at 425 for about 20 minutes, then reducing to 375 Fahrenheit. As long as the recipe tells you what the total cooking time of the chicken will be, you’ll be able to estimate the cooking time of the potatoes. Consider cooking other vegetables along with the potatoes. Root vegetables like parsnips, turnips and carrots all cook in the same time as potatoes, provided you cut them into uniform pieces. After removing the chicken and vegetables from the oven, make gravy from chicken or vegetable stock and the drippings from the roasting pan.