An impressive choice for a special occasion or holiday meal, the ribeye roast is a rich cut of beef with plenty of marbling to make it mouthwateringly tender. While cooking time is helpful for knowing how long you need to keep an eye on the oven, the temperature of your roast is the true indicator of when it’s done.
A 12-pound ribeye is a good-sized chunk of meat, so plan on roasting the beef for 5-1/2 to 6 hours, or about 28 to 33 minutes per pound, Oven temperatures can vary, so start checking for doneness around the 4-1/2 hour mark.
Checking for Doneness
The USDA recommends cooking beef to at least 145 F. Use a food thermometer to check the temperature, placing the tip in the center of the roast. Pull the roast out of the oven 5 to 10 degrees below your desired temperature. Let the roast rest, loosely covered in foil, for 15 minutes and the temperature will rise those extra 5 to 10 degrees.