Using a meat thermometer is the most accurate method to judge when turkey is done. Insert the thermometer into the thickest muscle of the breast or into the middle of the thick thigh muscle parallel to the bone and next to the body. Be sure the thermometer does not touch bone. When the turkey is cooked, the final reading should be 180 - 185ºF (82 - 85ºC) in the thigh and 170 - 175ºF (77 - 80ºC) in the breast.
If a meat thermometer is not available, pinch the thick muscle of the drumstick or the breast between cloth- or paper towel-protected fingers. The meat should feel soft and the leg will move easily when twisted. Another check is to run a long-tined fork into thick muscle; the meat should feel tender and the juice should show no pink tinge.