Prime Rib 500 Rule

The closed-oven prime rib 500 rule method delivers a beautifully crusted rib roast cooked to a perfect medium-rare. This foolproof technique is ideal for smaller boneless rib roasts, weighing 4 to 7 pounds. Learn how to prepare this delicious roast for your Christmas or holiday gathering!

Jump to:

• What is the Prime Rib 500 Rule?
• How to calculate the Prime rib 500 F rule
• This closed oven method is recommended for
• Can I use this 500 degree prime rib method if the roast is bigger than 7 lbs?
• Ingredients & Equipment
• Instructions
• How long to let prime rib rest
• Tips to ensure perfect prime rib every time
• How to avoid an undercooked rib roast
• What to do if the roast is too rare?
• What to serve with a small prime rib roast
• Frequently Asked Questions
• More Holiday recipes to try
• Prime Rib 500 Rule - Prime Rib Recipe

What is the Prime Rib 500 Rule?

The Prime Rib 500°F Rule is a simple formula for cooking a perfect medium-rare prime rib roast using the closed-oven method. This foolproof technique involves starting the roast at 500°F, effectively “searing” it at high heat to develop a rich, flavorful crust. Afterward, the oven is turned off, allowing the roast to continue cooking with residual heat until it reaches the desired medium-rare doneness.

How to calculate the Prime rib 500 F rule

To determine the "active" roasting time (the time you'll roast the meat at 500°F), simply multiply the weight of your roast (in pounds) by 5 minutes.

For example:

A 4-pound roast: 4 × 5 = 20 minutes

A 4.5-pound roast: 4.5 × 5 = 22.5 minutes (round up to 23 minutes).

This calculation ensures precise roasting for a perfect medium-rare result.

Here is an easy chart for reference!

*For half pound calculations, cooking time is rounded up.

This closed oven method is recommended for

1. Boneless, Small Prime Rib Roasts (4 to 7 Pounds):
This method is ideal for smaller, boneless cuts. Bone-in roasts don’t cook as evenly with this technique, as the meat near the bone tends to remain rare. To prepare, you can:

• Purchase a boneless prime rib roast.
• Ask your butcher to remove the bones.
• Debone the roast yourself if you’re comfortable doing so.

2. Medium-Rare Roasts:
This technique is ideal for achieving medium-rare doneness. If you prefer medium or well-done meat, this method is not suitable.

3. Ovens Without Cooling Fans:
It’s crucial that your oven doesn’t have an internal cooling fan. A cooling fan causes the oven to lose heat too quickly, preventing proper cooking. If your oven does have a cooling fan and you still want to try this method, here are your options:

• Option 1: Turn off the oven’s power at the breaker after completing the active roasting time.
• Option 2: Instead of turning the oven off, set it to the lowest possible temperature for the next two hours.

Can I use this 500 degree prime rib method if the roast is bigger than 7 lbs?

Yes, but with adjustments. For larger roasts:

• Ensure the roast is boneless.
• Cut the roast evenly in half to create two smaller roasts.
• Calculate the roasting time based on one rib roast.

Ingredients & Equipment

Small Boneless Rib Roast - I’m using a 4-pound roast, but this method works well for roasts between 4 to 7 pounds. 

Coarse Kosher Salt & Cracked Pepper - Use coarse kosher salt to create a flavorful crust. Avoid fine table salt, as it can make the roast overly salty.

Baking Rack - A baking rack is highly recommended for even cooking and to ensure a crisp crust on the bottom of the roast.

Timer - Keep a close watch on roasting time to ensure accuracy.

Kitchen twine - Use twine to tie the roast into a uniform shape for even cooking.

Baking or Roasting pan

Meath thermometer - Use an Instant-Read Thermometer for precise internal temperature readings

Instructions

1). Prepare the Roast:

Remove the roast from the refrigerator and let it sit at room temperature for at least 3 hours before roasting.

30 minutes before roasting, preheat the oven to 500°F. While the oven may reach 500°F quickly, wait the full 30 minutes to ensure it is thoroughly heated

2). Season Generously:

Season the roast generously with coarse kosher salt and cracked pepper.

Be sure to season all sides for maximum flavor.

3). Tie the Roast:

Use kitchen twine to tie the roast, ensuring it has a uniform shape for even cooking.

4). Start Roasting:

Place the roast on a baking rack set inside a roasting pan, with the fat side up.

Position the pan on the middle rack of the preheated oven.

Shut the oven door and set your timer for the active roasting time (calculated using the 500°F rule: roast weight × 5 minutes).

Turn Off the Oven: When the timer goes off, turn off the oven. Set another timer for 2 hours.

Do not open the oven door during this time. Place a visible sign or sticky note on the oven as a reminder not to peek.

After 2 hours, remove the roast from the oven, slice, and serve immediately. Pair it with au jus sauce and horseradish for the perfect accompaniment.

How long to let prime rib rest

With the 500°F no-peek method, there’s no need for an additional resting period after removing the roast from the oven. The roast naturally rests as the oven cools during the 2-hour no-peek phase, allowing the juices to redistribute and ensuring a tender, flavorful result.

Once the timer is up, the roast is ready to slice and serve immediately!

Tips to ensure perfect prime rib every time

• This recipe will not yield any pan drippings. 

• Use a Kitchen Scale:Accurately weigh your prime rib roast to calculate the correct cooking time using the 500°F Prime Rib Rule. This helps ensure the roast is cooked to a perfect medium-rare.

• Bring the Roast to Room Temperature: Make sure your roast is close to room temperature before cooking. A cold roast will cook unevenly, resulting in parts of the meat being too rare.

• Tie the Roast: Tying the roast with kitchen twine ensures even cooking and helps the roast maintain a uniform shape. This results in evenly cooked, round slices. Since one end of the roast may be smaller than the other, tying it creates an even circumference for better cooking.

• No Pan Drippings: This method does not produce pan drippings. Be sure to have a sauce or accompaniment like au jus or horseradish to serve with the roast.

• Ventilate Your Kitchen: This method can cause some smoke, so make sure your windows are open and fans are running to avoid setting off the smoke alarm.

How to avoid an undercooked rib roast

Use an Instant-read thermometer for more accurate reading. Insert the thermometer into the deepest part of the meat to check the internal temperature accurately.

Prime rib temperature reference guide:

• Rare: 120°F
• Medium-rare: 130°F
• Medium: 140°F
• Medium-well: 150°F
• Well-done: 160°F

What to do if the roast is too rare?

If your roast is undercooked or some guests prefer a more well-done portion, here are a few solutions:

Option 1: Put the Whole Roast Back in the Oven

If the entire roast is undercooked, return it to the oven at 300°F (150°C).

Cook in 10-minute intervals, checking the internal temperature frequently until it reaches your preferred doneness.

Option 2: Slice and recook.

If time is limited, slice the roast into individual portions.

Place the slices in the oven at 350°F (175°C) for about 10-15 minutes (depending on thickness) or until they reach the desired doneness.

Tip: Thinner slices cook faster, so adjust the thickness based on your serving timeline.

Option 3: Quick Sear

For guests who prefer their portion medium-well to well-done:

1. Heat a skillet with oil or butter on medium-high heat.
2. Add individual slices to the pan and sear for 1-2 minutes per side until they’re cooked to your liking.

Option 4: Reheat in sauce

Heat au jus or gravy in a pan until warm. Add slices of meat to the sauce and cook for 30 seconds or until they reach the desired doneness.

What to serve with a small prime rib roast

This recipe will not yield any pan drippings, pair the prime rib with this au jus recipe with beef broth, to serve alongside these easy Instant pot mashed potatoes, Green bean casserole with cream of chicken or Scalloped potatoes!

Frequently Asked Questions

More Holiday recipes to try

Love a recipe you've tried? Please leave a 5-star 🌟rating in the recipe card and a comment below! That'll make my day!

Let's be friends! Follow me on social media @ Instagram, Pinterest. Give me a tag @apeachyplate when you try out a recipe!