The first thing to keep in mind while cooking a turkey is the amount of time that is required for the turkey to be roasted. Although it will vary depending on the size and weight of the turkey, one can make a rough idea about it by citing the example that a ten pound turkey will take around four hours to be roasted properly. What you would need to do after this is take a meat thermometer and insert it inside the upper thigh of the bird. You have to be careful to keep the tip of the thermometer inside the meat only, so that it does not touch the bone deeper inside.
A turkey must be free of bacterial growths, if there is any. In order to do that, the thermometer you had put inside the turkey must show a temperature of roughly 165° F to 175° F. This temperature differs from one cook to another because some cooks feel that the temperature is too high to produce soft, juicy meat afterwards. But, the US Department of Agriculture disagrees and suggests that 165° F is definitely the temperature that a meat thermometer inside the innermost region of the bird’s thigh should read. The temperature that you will record in the thighs will however not be the same throughout the turkey’s body because the portion near the breast is likely to be hotter by at least 10° F. The dark meat has a tendency to get overcooked very easily.
Apart from these theoretical suggestions, there is also an on the spot method to check if your turkey is done. Check the portion of the turkey’s thigh where you had earlier inserted the meat thermometer into; it should be leaking some juices at this point and it is by looking at the color and texture of the juice that you can make out whether the bird is done. The juices running from the gap or anywhere else should be clear and that would indicate the fact that the meat is done. However, it will not be the case if you have smoked the bird because then the meat would be pink.