Roast Beef Cooking Time Calculator
Calculate roast beef cook time and oven temperature by weight and doneness.
Returns total time, internal target temp, and resting time per pound.
Roast beef timing depends on three things: the cut, the weight, and the doneness you are aiming for. A meat thermometer is more reliable than the clock, but knowing the rough time helps you plan when to start cooking.
Standard times for a boneless beef roast cooked at 325 F (163 C):
- Rare: 18-20 min per lb, internal 125 F (52 C)
- Medium-rare: 20-22 min per lb, internal 130 F (54 C)
- Medium: 22-25 min per lb, internal 140 F (60 C)
- Medium-well: 25-28 min per lb, internal 150 F (66 C)
- Well done: 28-32 min per lb, internal 160 F (71 C)
For a 4 lb roast aiming for medium-rare:
4 lbs x 21 min/lb = 84 min (about 1 hour 24 min)
Two adjustments matter:
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Pull early. Carryover cooking raises the internal temperature 5 to 10 F after you take it out. Pull at 125 F for medium-rare, not 130 F. The center keeps cooking for 10 to 15 minutes while it rests.
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Reverse-sear option. Cook at 250 F (120 C) until 10 F below target, then sear at 500 F for 5 minutes. This gives you a more even doneness from edge to center, and the timing is closer to 30 to 40 min per lb at the low temp. Better for cuts thicker than 4 inches.
Cuts and what to expect:
- Eye of round: lean, takes well to medium-rare; tough above medium
- Top round: mid-priced, sliceable, holds up to medium
- Sirloin tip: budget choice, best at medium-rare
- Tenderloin: premium, fast-cooking, only do medium-rare or rare
- Prime rib (standing rib): cook at 450 F for 15 min, then 325 F for 13-15 min/lb to medium-rare
Always rest. Cut into a hot roast and the juices flood the cutting board; cut into a rested roast and they stay in the meat. Rest time:
- Under 3 lbs: 10 minutes
- 3 to 6 lbs: 15 to 20 minutes
- Over 6 lbs (prime rib, standing rib): 25 to 30 minutes
Tent loosely with foil during the rest. A tight wrap keeps too much heat and continues cooking past your target.