How Long to Cook Prime Rib Per Pound (For All Types of Doneness)

Want to know how long it will take you to cook your prime rib to perfection?

Whether you are cooking for yourself or guests you want to make sure you cook it to your desired doneness. 

Plus it’s an expensive cut, so you don’t want to mess it up! 

But how do you work out the cooking time?

Are there any other factors to consider?

Make sure you follow my steps below to cook your prime rib to perfection! 

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Calculating the Cooking Time

To work out the minutes per pound, you need to factor in 2 other things.

What is your smoker or oven temp?

Do you prefer rare, medium, or well-done prime beef?

What Is Your Preferred Doneness?

Cuts of beef can be cooked at different internal temperatures.

The degree of doneness is based on personal preference.

Rare – 125°F any less than this would be considered undercooked
Medium – 135°F
Well done – 155°F

What Is the Cooking Temperature?

The smoker or oven temperature for your cooking process will change how long it takes.

The minutes per pound it takes for an entire roast can change drastically based on temp.

Below I have detailed the prime rib cooking time at 4 different temperature points.

As well as the adjustments needed for each level of doneness.

So you can be sure your perfect prime rib roast recipe is perfect!

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How Long to Cook Prime Rib per Pound at 225°F

Rare Prime Rib

rare prime rib cooks for 35 minutes per pound at 225°F.

Medium Prime Rib

A medium prime rib cooks for 40 minutes per pound at 225°F.

Well Done Prime Rib

A well-done prime rib cooks for 45 minutes per pound at 225°F.

Example of How Long a Medium Prime Rib Roast Takes at 225°F

Let’s say you want a perfect medium-rare prime rib.

It has been weighed as a 4-5 pound roast and your oven heat is set to 225°F.

4.5 (average weight) x 40 (minutes for medium) = 180 minutes. 

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How Long to Cook Prime Rib per Pound at 250°F

Rare Prime Rib

A rare prime rib cooks for 30 minutes per pound at 250°F.

Medium Prime Rib

A medium prime rib cooks for 35 minutes per pound at 250°F.

Well Done Prime Rib

A well-done prime rib cooks for 45 minutes per pound at 250°F.

Example of How Long a Medium Prime Rib Roast Takes at 250°F

For a delicious 4-pound standing rib roast cooked medium?

4 (weight) x 35 (minutes for medium) = 140 minutes.

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How Long to Cook Prime Rib per Pound at 300°F

Rare Prime Rib

A rare prime rib cooks at a rate of 20 minutes per pound at 300°F.

Medium Prime Rib

A medium rib cooks at a rate of 25 minutes per pound at 300°F.

Well Done Prime Rib

A well-done prime rib cooks at a rate of 30 minutes per pound at 300°F.

Example of How Long a Medium Prime Rib Roast Takes at 300°F

This piece of meat weighs 8 pounds for a large dinner party!

8 (weight) x 25 (minutes for medium) = 200 minutes.
Note:
The pound of meat example changes each time.

Which gives you a different actual cooking time.
This will help you get in the habit of checking the weight for your cooking methods!

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How Long to Cook Prime Rib per Pound at 350°F

Rare Prime Rib

A rare prime rib cooks for 15 minutes per pound at 350°F.

Medium Prime Rib

A medium prime rib cooks for 20 minutes per pound at 350°F.

Well Done Prime Rib

A well-done prime rib cooks for 25 minutes per pound at 350°F.

Example of How Long a Medium Prime Rib Roast Takes at 350°F

If you plan on smoking a prime rib that weighs 5 pounds see the calculations for it below. You can also see how many people that would feed here.

5 (weight) x 20 (minutes for medium) = 100 minutes

What Is the Best Temp to Cook a Prime Rib Recipe?

As a rule of thumb, a low and slow temp with indirect heat is the best.

Cook at a temperature of 225°F or 250°F and let the meat rest for at least 20 minutes.

At this temp, the meat juice will absorb back into the proteins.

It also allows the outer layers of fat and connective tissue to render.

Forming a delicious crust with amazing flavor and texture on the meat.

Note: Read further to understand how the resting process can affect the cooking time.

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What Is the Best Level of Doneness for a Prime Rib?

A perfect medium-rare prime rib is the traditional method of doneness.

Overcooked meat will dry out and ruin your beef roast.

Rare beef is best saved for cuts without fat like an eye roast.

The higher fat content in a prime rib requires more time to render.

Accurately Monitoring the Internal Temperature With a Meat Thermometer

Arguably the most important tool in all your cook time!

Have a calibrated meat thermometer to know the internal temperature accurately.

These are a type of instant-read thermometers you insert before cooking.

They update you in real time for an accurate reading.

Temperature control is key for a successful cook.

As well as liberal seasoning with kosher salt and black pepper!

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Remember That the Timings Are Estimations

A little disclosure for working out an exact cooking time.

You will never get one!

It is nearly impossible and the above timings should be used as a guide.

So use a digital meat thermometer based on the above internal temps.

Additional Cooking Time When Resting

Cover with aluminum foil or butcher paper while resting.

The internal temp will rise by about 10°F during this process.

Which is known as carryover cooking.

Remove from your hot oven or grill a little bit before your required perfect temperature.

Keep a cooking thermometer in so you can monitor it while resting.

Why Were My Estimations So Wrong?

Below are some reasons why your calculation was out.

USDA choice prime beef is delicious and expensive.

Don’t let it burn!

You Didn’t Trim the Fat Cap

There is a large fat cap on the prime rib which needs to be trimmed to 1 inch.

Ask your butcher to do this for you or use a sharp knife.

Thick subcutaneous fat will deflect heat energy.

Which means it slows down the cooking process!

how-long-to-cook-prime-rib

Is Your Piece of Meat Bone-in or Bone-Out?

Have you got a bone-in roast or a boneless roast?

Bone-in Roast

The weight of the bone can affect the cooking time.

It also retains the residual heat for longer.

Which can cause increased carryover cooking.

Cooking Tips & Timing Estimations For Rib Bones

– Subtract a pound from the total weight. 

– Do not put your temperature probe directly on the meat.

– Remove the beef rib bone with a sharp carving knife a few minutes before carving.

Boneless Rib Roast

A boneless prime roast cooks evenly as per the above timings.

Rest well before carving to ensure the flavorful juices have been reabsorbed!

Smoke On!

Charlie

Author: Charlie Reeves
Hi, I’m Charlie, I am head taste tester at Simply Meat Smoking! I love it grilling, smoking, and getting out in the yard with the kids! The family also love to test all my recipes (especially my EXTRA CRISPY pulled pork, smoky pork loin, and ANY SEAFOOD I grill)

You will usually find me playing with the kids, perfecting my brisket bark, or sipping beers with boys around the fire. Can’t wait to share all my delicious smoking and grilling adventures with you!

You can read more on our About Us page.

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