Roast size, meat type, and oven temperature all influence how many minutes per pound your roast will need to reach the perfect internal temperature. So when someone asks how long do you cook a roast in the oven, the honest answer is that it depends on what your cooking. A small chicken roast and a big beef rib roast follow very different timers.
This guide breaks down the numbers by meat type, gives you a simple chart-style method, and shows you how to check doneness without guessing. Read the section for your roast, set your timer, and use a meat thermometer to confirm.
How Long Do You Cook A Roast In The Oven
The short version: most roasts cook at 325°F to 375°F, and most need roughly 15 to 25 minutes per pound. But that range is wide, so you need to narrow it down by meat and cut.
Here is the general rule most cooks rely on:
- Beef roast: 18 to 22 minutes per pound at 325°F for medium
- Pork roast: 20 to 25 minutes per pound at 325°F
- Chicken or turkey roast: 20 minutes per pound at 350°F
- Lamb roast: 20 to 25 minutes per pound at 325°F
These times are a starting point, not a guarantee. Your oven runs hot or cold, your roast shape varies, and bone-in cuts cook differently than boneless ones. Always finish with a thermometer.
Why Minutes Per Pound Is Only A Estimate
Two roasts of the same weight can finish 30 minutes apart. A long, flat roast has more surface area and cooks faster. A thick, round roast takes longer to push heat into the center.
Bone-in roasts also cook a bit faster near the bone, but the bone can slow things down in other spots. And a roast straight from the fridge needs more time then one that sat on the counter for 30 minutes.
So use minutes per pound to plan, then trust your thermometer to decide.
Beef Roast Cooking Times By Cut
Beef is the most common roast people search for, so lets cover the main cuts.
Prime Rib And Ribeye Roast
Cook at 325°F. Plan on 18 to 20 minutes per pound for medium rare. A 5-pound rib roast usually takes about 1 hour 45 minutes to 2 hours.
Pull it at 125°F for rare, 135°F for medium rare, and 145°F for medium. Rest it 20 minutes before carving.
Beef Tenderloin Roast
Tenderloin is lean and cooks fast. Use 425°F for the first 15 minutes, then drop to 325°F. Count on 15 to 18 minutes per pound total. A 3-pound tenderloin is often done in 45 to 55 minutes.
Chuck Roast And Pot Roast
These tougher cuts need low and slow heat. Cook at 300°F to 325°F for 2.5 to 3.5 hours, or about 45 minutes per pound. They are done when they shred with a fork, not when they hit a specific temp.
Sirloin Tip And Round Roast
Use 325°F and 20 to 22 minutes per pound for medium rare. These cuts are leaner, so do not overcook them or they turn dry.
Pork Roast Cooking Times
Pork is safe at 145°F with a 3-minute rest. Many people still cook it to 160°F, but that dries it out.
Pork Loin Roast
Cook at 350°F for 20 minutes per pound. A 4-pound loin takes about 1 hour 20 minutes. Target 145°F in the thickest part.
Pork Shoulder And Butt
This cut needs 300°F and 35 to 40 minutes per pound. A 6-pound shoulder can take 3.5 to 4 hours. Cook it to 195°F to 205°F so it pulls apart.
Pork Tenderloin
Small and quick. Roast at 425°F for 20 to 25 minutes total, no per-pound math needed. Pull at 145°F.
Poultry Roast Cooking Times
Chicken and turkey follow a simple rule: 350°F and 20 minutes per pound.
- 3-pound chicken: about 1 hour
- 5-pound chicken: about 1 hour 40 minutes
- 12-pound turkey: about 3 hours 15 minutes
- 20-pound turkey: about 4 hours 30 minutes
Cook poultry to 165°F in the thigh, not the breast. The thigh is the last spot to reach temp, so it tells you the truth.
Lamb Roast Cooking Times
Lamb works well at 325°F. Leg of lamb takes 20 to 25 minutes per pound for medium rare. A 5-pound leg runs about 1 hour 45 minutes.
Rack of lamb is smaller and faster. Sear it at 450°F for 10 minutes, then cook at 350°F for 15 to 20 more minutes. Pull at 130°F for medium rare.
Step By Step: How To Cook Any Roast
- Take the roast out of the fridge 30 to 60 minutes before cooking.
- Heat your oven to the temp listed for your meat.
- Pat the roast dry and season it well with salt and pepper.
- Place it fat side up on a rack in a shallow pan.
- Roast uncovered so the surface browns.
- Start checking temp about 20 minutes before your estimated finish time.
- Pull the roast when it hits your target temp.
- Cover it loosely with foil and rest 15 to 20 minutes.
The rest matters. It lets juices settle and the temp rise another 5 to 10 degrees. If you skip it, you lose juice on the cutting board.
Internal Temperature Targets
Use these numbers as your real guide. The clock is only a backup.
- Beef rare: 125°F
- Beef medium rare: 135°F
- Beef medium: 145°F
- Pork: 145°F
- Pork shoulder: 195°F to 205°F
- Chicken and turkey: 165°F
- Lamb medium rare: 130°F
Stick the thermometer into the thickest part, away from bone and fat. Check two spots if the roast is uneven.
Common Mistakes That Change Cooking Time
Opening The Oven Too Often
Every time you open the door, heat escapes and the cook time grows. Use the oven light instead.
Using The Wrong Pan
A deep roasting pan with high sides steams the meat instead of roasting it. Use a shallow pan with a rack when you can.
Not Letting The Oven Preheat Fully
If you put the roast in early, the first 10 minutes are off. Wait for the preheat beep.
Trusting The Timer Over The Thermometer
This is the big one. Ovens vary by 25 degrees or more. The thermometer is the only thing that tells you the truth.
Quick Reference Summary
Here is the whole article in one place.
- Beef rib or prime rib: 325°F, 18 to 20 min per pound
- Beef tenderloin: 425°F then 325°F, 15 to 18 min per pound
- Beef chuck: 300°F, 45 min per pound
- Pork loin: 350°F, 20 min per pound
- Pork shoulder: 300°F, 35 to 40 min per pound
- Chicken or turkey: 350°F, 20 min per pound
- Lamb leg: 325°F, 20 to 25 min per pound
So the next time your planning a roast dinner, pick your meat, set your oven, and do the math. Then grab your thermometer and let it make the final call. Thats how you get a roast that comes out right every time, no matter the size.