how long do you have to cook a 6 pound prime rib?

According to Prime Steakhouses, no matter what size roast you have, you will start it in a pre-heated 450 degree oven for 15 minutes then reduce the temperature to 325 degrees for the balance of cooking time.

Cooking times will vary depending on size of the roast and desired level of doneness. The following chart gives approximate times for to reach "rare" at various sizes.

Cooking Time for Rare (120°)

• (3) Ribs, 7 to 8 lbs. 15 minutes at 450°, Then 1 ¼ to 1 ½ hours at 325°
• (4) Ribs, 9 to 10 lbs. 15 minutes at 450°, Then 1 ½ to 2 hours at 325°
• (5) Ribs, 11 to 13 lbs. 15 minutes at 450°, Then 2 to 2 ½ hours at 325°
• (6) Ribs, 14 to 16 lbs. 15 minutes at 450° Then, 2 ¾ to 3 hours at 325°
• (7) Ribs, 16 to 18 lbs. 15 minutes at 450° Then, 3 to 3 ¾ hours at 325°

To cook a prime rib roast:

• Preheat your oven to 450 degrees.
• Use a paper towel to pat the roast dry.
• Rub butter on the cut ends of the roast.
• Create a seasoning rub or paste with ingredients such as pepper, coarse salt, garlic powder, and onion powder. Make a series of ½ inch deep slits all over the top of the roast as well as the sides. Rub your seasonings all over the roast, covering all exposed meat.
• Place the roast in a heavy metal roasting pan, bone-side down.

To check doneness, use a meat thermometer about a half hour before the expected end of the roasting time. Make sure to insert it in the thickest part of the meat, not touching the fat or bone. When the internal temperature reaches 120°, pull it out of the oven and cover with foil.

Let the roast sit for twenty to thirty minutes. It will continue to cook during this time, reaching a temperature of about 125° to 130°. This resting period allows the juices and flavors to permeate the roast.

Rare meat reaches 120° to 125°. Medium rare meat measures between 130° to 135°. Medium meat measures about 140° to 145°. Medium well is at 150° to 155°. Well done is achieved at about 160°.

Learn how to cook prime rib at recipetips.com.

Get tips on how to purchase a prime rib roast at Whats Cooking America.

Prime rib is prime-time party food! Check out great prime rib recipes to make your feast festive at Food Network.