How Does Using a Convection Oven Affect Slow-Roasting Cooking Times?

For visitors entering my website on this page, Click here to find out more about my no-guess method for how to cook turkey. It will help you understand the turkey roasting time chart below.

These times assume that you're cooking your turkey without stuffing. I do not recommend cooking your stuffing inside the turkey. Stuffing plays havoc with the cooking time. There are several health issues to consider when cooking stuffing inside. I don't do it and recommend that you don't do it either. Cook the stuffing in a separate casserole dish and you know you'll be OK. It's OK to over eat, but I want everyone healthy on Thanksgiving.

There are many variables that come into play when cooking a turkey. How accurate is temperature in your oven? Has the turkey been totally thawed?

The only way to be absolutely sure that your turkey is fully cooked is to use a quality meat thermometer. Interior breast meat should be 170°F and 180°F for thigh meat.

Using a meat thermometer is particularly important if you are roasting the turkey a high elevations since it will take longer but there is no rule of thumb to predict how much longer. Give yourself some extra time before you're planning to sit down to eat if cooking at a high elevation.

If your oven is accurate and your turkey has been completely thawed, the turkey cooking time chart below should give you a perfect turkey. But always use a meat thermometer to be sure.

Note: You do not remove the turkey from the oven after the first 20 minutes at 475° to wait for the oven temperature to fall to 250°. You just turn the oven down to 250° and immediately start the timer for the time to cook at 250°.

Examples of  Roasting Times for Common Turkey Sizes
Using This Slow-Cook Method
  U.S. use °F, Europe use °C    
Size Turkey Time at 475°F
(246°C)
Time at 250°F
(121°C)
"Resting" Time Total Preparation Time
10 lbs. 20 minutes 3 hours 20 minutes 20 minutes 4 hours
11 lbs. 20 minutes 3 hours 40 minutes 20 minutes 4 hours 20 minutes
12 lbs. 20 minutes 4 hours 20 minutes 4 hours 40 minutes
13 lbs. 20 minutes 4 hours 20 minutes 20 minutes 5 hours
14 lbs. 20 minutes 4 hours 40 minutes 20 minutes 5 hours 20 minutes
15 lbs. 20 minutes 5 hours 20 minutes 5 hours 40 minutes
16 lbs. 20 minutes 5 hours 20 minutes 20 minutes 6 hours
17 lbs. 20 minutes 5 hours 40 minutes 20 minutes 6 hours 20 minutes
18 lbs. 20 minutes 6 hours 20 minutes 6 hours 40 minutes
19 lbs. 20 minutes 6 hours 20 minutes 20 minutes 7 hours
20 lbs. 20 minutes 6 hours 40 minutes 20 minutes 7 hours 20 minutes