Defrosting A Turkey At Room Temperature. Cooked turkey that has been left out for longer than 2 hours or 1 hour above 90 F should be discarded. To work out the defrosting time for your turkey first check the packaging for any guidance.
Defrosting times will vary as a guide. Check the pack instructions to be sure but an approximate thawing guide is 10-12 hours per kilogram in a fridge at 4C. The laws of physics are apparently different north of the 49th parallel and poultry is required to reach 180F.
When thawing a turkey in the refrigerator allow 24 hours of defrosting time for every 4 to 5 pounds of bird according to the US.
To work out the defrosting time for your turkey first check the packaging for any guidance. That gives you the temperature difference you want at the end of roasting 150 degrees in. In a cool room below 175ºC allow three to four hours per kg. That works out to be 12 hours per kilogram for a turkey in a fridge set at 4 degrees C.