Last updated: November 1, 2026
Here is how to cook prime rib: season the roast, set it fat side up on a rack in a shallow pan, and roast it uncovered at 325°F until a thermometer in the center reads 5 to 10°F below your target doneness. A bone-in roast takes about 23 to 30 minutes per pound. Rest it before carving.
This guide combines the roasting chart from the USDA Food Safety and Inspection Service with beef industry timing and doneness charts.
Contents
- How to cook prime rib step by step
- Prime rib cooking time per pound
- Prime rib temperature chart for doneness
- How much prime rib per person
- What is prime rib?
- How to carve prime rib
- Storing leftover prime rib
- Frequently asked questions
How to cook prime rib step by step
- Buy the right size. Plan on one rib for every two people for a bone-in roast.
- Season the roast. Salt and pepper are enough, or use a rub with garlic and herbs.
- Heat the oven. Preheat to 325°F. For a browned crust, many cooks start at 450°F for about 15 minutes, then lower the heat to 325°F.
- Set it up to roast. Place the roast fat side up on a rack in a shallow, uncovered pan.
- Insert a thermometer through the side of the roast so the tip sits in the center, not touching bone or fat.
- Roast by temperature, not only time. Use the charts below to estimate, and start checking early.
- Pull it early. Remove the roast when it is 5 to 10°F below your target doneness.
- Rest, then carve. Tent loosely with foil for 10 to 15 minutes, then slice.
The USDA explains that roasting means cooking meat on a rack in a shallow, uncovered pan with the dry heat of the oven, and that a moderately low 325°F keeps tender meat juicy and limits shrinkage. It does not recommend oven temperatures below 325°F, because the meat could stay too long in the “Danger Zone” of 40 to 140°F, where bacteria multiply rapidly. The 450°F start and 325°F finish come from Certified Angus Beef cooking times, which suggests planning about 30 extra minutes for the sear and the rest.
Prime rib cooking time per pound
Time per pound is a planning estimate, not a finish time. Roast shape, oven accuracy and the starting temperature of the meat all change the result. The USDA notes that boned and rolled roasts need more time per pound than bone-in cuts, because heat takes longer to reach the center of solid meat.
USDA roasting times at 325°F
| Roast | Weight | Oven | Time |
|---|---|---|---|
| Rib roast, bone-in | 4 to 8 lb | 325°F | 23 to 30 min per lb |
| Rib roast, boneless | 4 lb | 325°F | 39 to 43 min per lb |
For example, a 6 pound bone-in roast at 23 to 30 minutes per pound needs roughly 2 hours 18 minutes to 3 hours.
Bone-in prime rib cooking times at 350°F
Beef. It’s What’s For Dinner gives total roasting times for a bone-in ribeye roast in a preheated 350°F oven:
| Weight (ribs) | Medium rare (remove at 135°F) | Medium (remove at 145°F) |
|---|---|---|
| 4 to 6 lb (2 ribs) | 1¾ to 2¼ hours | 2¼ to 2¾ hours |
| 6 to 8 lb (2 to 4 ribs) | 2¼ to 2½ hours | 2½ to 3 hours |
| 8 to 10 lb (4 to 5 ribs) | 2½ to 3 hours | 3 to 3½ hours |
These are the temperatures at which to take the roast out of the oven. The same source notes that the internal temperature keeps rising by 10 to 15 degrees after the roast comes out, so the final doneness will be a little higher.
Sear-then-roast times (450°F, then 325°F)
Certified Angus Beef lists these approximate times for a bone-in ribeye roast:
| Weight | Rare (125°F) | Medium (145°F) |
|---|---|---|
| 4 lb | 1 hr 45 min | 2 hr 9 min |
| 5 lb | 1 hr 51 min | 2 hr 18 min |
| 6 lb | 1 hr 57 min | 2 hr 26 min |
| 7 lb | 2 hr | 2 hr 33 min |
| 8 lb | 2 hr 11 min | 2 hr 41 min |
Planning a full holiday menu? Our guide to how long to cook a turkey covers turkey times by weight, and the cooking conversion chart helps when a recipe uses unfamiliar measurements.
Prime rib temperature chart for doneness
A thermometer is the only reliable way to know when prime rib is done. Certified Angus Beef lists these final temperatures and advises removing a roast from the heat when it reads 5 to 10°F lower, because the temperature keeps rising as it rests:
| Doneness | Center | Final temperature | Remove from oven at about |
|---|---|---|---|
| Rare | Cool red center | 125°F (52°C) | 115 to 120°F |
| Medium rare | Warm red center | 135°F (57°C) | 125 to 130°F |
| Medium | Warm pink center | 145°F (63°C) | 135 to 140°F |
| Medium well | Slightly pink center | 150°F (66°C) | 140 to 145°F |
| Well done | Little or no pink | 160°F (71°C) | 150 to 155°F |
What the USDA recommends
The USDA says to cook raw beef roasts to a minimum internal temperature of 145°F, measured with a food thermometer, and to let the meat rest for at least 3 minutes before carving. It adds that consumers may choose higher temperatures for personal preference. Rare and medium rare prime rib are below that guideline. For other meats, see what temperature pork should be cooked to, and if your thermometer reads in Celsius, use the Celsius to Fahrenheit conversion chart.
How much prime rib per person
Beef. It’s What’s For Dinner recommends a bone-in prime rib with one rib for every two people. When cooking for four people or fewer, it suggests buying steaks instead or asking the meat counter for the roast size you need.
| Guests | Ribs (bone-in) |
|---|---|
| 4 | 2 |
| 6 | 3 |
| 8 | 4 |
| 10 | 5 |
What is prime rib?
Prime rib is a ribeye roast cut from the rib primal. At the store it may be labeled standing rib roast, holiday roast or ribeye roast, and it is sold bone-in and boneless. It is savory and fine textured, with generous marbling.
Is prime rib the same as USDA Prime?
Not necessarily. “Prime rib” names the cut, while USDA Prime is a quality grade. Under the USDA beef grading standards, Prime requires at least a “slightly abundant” amount of marbling, more than the “small” amount required for Choice. The roast in the photo above, for example, is a USDA Choice standing rib roast.
How to carve prime rib
Beef. It’s What’s For Dinner recommends this method:
- Turn the rested roast on its side.
- Cut along the curve of the ribs, as close to the bones as you can, holding the roast steady with a serving fork or tongs.
- Turn the boneless roast fat side up.
- Slice to your preferred thickness.
Storing leftover prime rib
The USDA leftovers guidance says to refrigerate cooked food within 2 hours, or within 1 hour if the room is above 90°F. Leftovers keep 3 to 4 days in the refrigerator or 3 to 4 months in the freezer.
Frequently asked questions
How long do you cook prime rib per pound?
At 325°F, the USDA lists 23 to 30 minutes per pound for a 4 to 8 pound bone-in rib roast and 39 to 43 minutes per pound for a 4 pound boneless rib roast. Always confirm doneness with a meat thermometer.
What temperature should prime rib be cooked at?
Roast prime rib at 325°F to 350°F. The USDA recommends an oven of at least 325°F, and many cooks sear the roast at 450°F for about 15 minutes before lowering the heat.
What internal temperature is prime rib done?
Certified Angus Beef lists 125°F for rare, 135°F for medium rare and 145°F for medium. The USDA recommends cooking beef roasts to at least 145°F and resting them for 3 minutes.
How much prime rib do I need per person?
Beef. It’s What’s For Dinner recommends buying a bone-in prime rib with one rib for every two people.
Do you cover prime rib when cooking it?
No. Roast prime rib uncovered on a rack in a shallow pan, fat side up, then tent it loosely with foil while it rests.
How long should prime rib rest before carving?
Rest prime rib 10 to 15 minutes, tented with foil, before slicing. Its internal temperature keeps rising by about 10 to 15 degrees after it leaves the oven.
Sources
- USDA FSIS: Roasting Those “Other” Holiday Meats
- USDA FSIS: Leftovers and Food Safety
- USDA AMS: Carcass Beef Grades and Standards
- Beef. It’s What’s For Dinner: All About Prime Rib
- Certified Angus Beef: Degree of Doneness
Image: USDA Choice standing rib roast (2 bone), by Michael C. Berch, licensed CC BY-SA 2.5, resized, via Wikimedia Commons.
