How Long To Cook Beef Roast

Beef Roast Cooking Times Explained

How Long To Cook Beef Roast by Cut and Weight

The short answer is roughly 20 minutes per pound at 325°F for medium-rare, but that formula falls apart if you don't know what you're working with. A boneless chuck roast behaves completely differently than a prime rib, and slapping the same time on both will get you a shoe leather mess or a gray well-done disaster. The real variable isn't time. It's internal temperature, and using a probe thermometer is non-negotiable if you want consistent results. I've lost count of the roasts I've pulled too early or left in way too long because I was guessing. About three years ago I had a 7-pound brisket point that came out of the oven at exactly the target temp according to the clock, but when I cut into it the connective tissue hadn't broken down yet. It was tough enough to require a knife and fork like a steak. I threw it back in at 275°F with a cup of broth in the pan for another two hours. That lower temperature gave the collagen time to convert to gelatin without further drying out the muscle fibers. The difference between tough and melting was purely a matter of patience and temperature, not timing. Here is what actually works in practice, organized by the most common cuts you will encounter at the store or butcher counter.

Rib Roast (Prime Rib): This is the expensive one and the one people overcook most often. Aim for 120-125°F internal for medium-rare, pulling it out of the oven about 5-10°F before that target because carryover cooking will add those degrees while it rests. At 350°F this takes roughly 15 minutes per pound for rare, 18 minutes per pound for medium-rare. A 5-pound rib roast typically lands in the oven for just over an hour and a half. The critical step most people skip is resting it under loosely tented foil for at least 20 minutes before carving. If you cut into it immediately, the juices run out onto the board and every slice comes out drier than it should be. Chuck Roast: This cut has more connective tissue and collagen, which means the 20-minutes-per-pound rule at high heat will make it dry and tough. Chuck roast benefits from low and slow cooking. Wrap it in foil with a bit of liquid and cook it at 275-300°F for about 3-4 hours for a 3-4 pound roast until it reaches around 203°F internal. That higher target temperature is what you need to dissolve the collagen properly. If you pull it at 145°F like a tenderloin, you will have chewy meat. The target temperature is backwards from what you might expect compared to prime rib, but that is just how this cut works. Round Roast: Bottom round, top round, and eye of round are all lean cuts from the hindquarters. They cook fast but dry out fast. Bottom round at 325°F for about 20-25 minutes per pound for medium-rare at 130-135°F internal. Eye of round is even leaner and usually cooks in the 15-18 minute per pound range. The problem with round roasts is that they have very little marbling, so there is zero margin for error. Go 10 degrees past your target and you are eating jerky. Many people braise round roasts instead of dry roasting them precisely because the margin for failure is so slim.

Brisket: This is a different beast entirely. A packer brisket weighing 10-15 pounds will take 4-6 hours at 225-250°F if you are smoking or using low-and-slow oven methods. The stall happens around 150-170°F internal where evaporative cooling causes the temperature to plateau for hours. You can wrap it in butcher paper or foil at that point to push through the stall, which usually adds about an hour to the total cook time. The target internal temperature is 200-205°F, checked by probing the thickest part of the flat. It should feel like going into soft butter when done correctly. Tenderloin (Filet Mignon roast): This is the most forgiving cut because it is already so tender. It cooks quickly at high heat. At 425°F, a 2-pound tenderloin takes roughly 25-30 minutes to reach 125-130°F for medium-rare. Because it is so lean and uniform in shape, it cooks very evenly. The main risk here is the ends drying out. Tying the roast with kitchen twine at the thinner ends creates a more uniform shape and helps everything cook at the same rate. Rest for 10-15 minutes before slicing. The biggest mistake home cooks make is treating every roast the same way. A standing rib roast and a pot roast from the same animal need completely different approaches because of where they come from and how much work the muscle did while the animal was alive. More movement means more connective tissue, which means lower heat and longer time. Less movement means less collagen, which means higher heat and shorter time. That is the rule that matters more than any chart you will find online.

Another thing that trips people up is oven calibration. That 325°F on your oven dial might actually be 290°F or 360°F inside. I bought a separate oven thermometer a while back after noticing my roasts were consistently undercooked relative to the clock. Most ovens run 25-50°F off from what the dial says. Checking yours takes five minutes and will immediately improve your results. If you are new to this, start with a chuck roast braised at low heat. It is nearly impossible to ruin and the margin for error is wide. Once you understand how collagen responds to time and moisture, the other cuts start making more sense. There is no shortcut around learning the relationship between cut, temperature, and time, but once you have it dialed in the whole process becomes routine rather than a gamble.