Christmas ham, prime rib, a pork crown or a leg of lamb
Ham, prime rib, pork and lamb cooking times
At 325 °F, USDA FSIS times a bone-in beef rib roast (prime rib) of 4 to 8 lb at 23 to 30 minutes per pound, cooked to 145 °F (62.8 °C) and rested at least 3 minutes. A whole, bone-in, fully cooked ham takes 15 to 18 minutes per pound to reheat to 140 °F (60 °C), and a cook-before-eating ham of the same size 18 to 20 minutes per pound to 145 °F. Pick your cut and weight for the time in hours and minutes.
USDA FSIS · Beef
Roasting time
2 h 18 min to 3 h
Beef, rib roast, bone in, 6 lb (2.7 kg)
Oven
325 °F (163 °C)
FSIS rate
23 to 30 minutes per lb, for 4 to 8 lb
Cook to
145 °F (62.8 °C), then rest at least 3 minutes
Start checking
after 2 h 18 min
1:00 pm In the oven
3:15 pm Start checking the temperature
4:00 pm Out by now, once it reaches temperature
4:03 pm Carve, after at least 3 minutes' rest
FSIS calls these approximate times for meal planning. Check the thickest part, away from bone, with a food thermometer.
Which ham do you have?
The label decides everything: how long the ham needs, and whether you are cooking it or only warming it through.
Read the label first: three hams, three targets.
Fresh ham is an uncured leg of pork. FSIS says a ham made without a cure must be labelled “fresh” or “uncured”. It is raw: cook it to 145 °F (62.8 °C) and let it rest at least 3 minutes.
Cook-before-eating ham has been cured or smoked but not cooked. It also goes to 145 °F with a 3-minute rest.
Fully cooked ham, labelled “cooked” or “fully cooked”, needs no cooking at all. FSIS says it can be eaten cold or reheated: to 140 °F (60 °C) if it was packaged in a USDA-inspected plant, and to 165 °F (73.9 °C) otherwise. Spiral-cut, canned and vacuum-packed hams are in this group.
Country ham is dry-cured and follows its own method: FSIS says to soak it in the refrigerator for 4 to 12 hours, cover it with water and boil it for 20 to 25 minutes per pound, then drain, glaze and brown it at 400 °F for 15 minutes.
Smoked ham, fully cooked, spiral cut, whole or half
7 to 9 lb 3.2–4.1 kg
10–18 min/lb 22–40 min/kg
140 °F (60 °C)*
Ham, fully cooked, boneless
3 to 4 lb 1.4–1.8 kg
27–33 min/lb 60–73 min/kg
140 °F (60 °C)*
Smoked ham, fully cooked, vacuum packed, boneless
6 to 12 lb 2.7–5.4 kg
10–15 min/lb 22–33 min/kg
140 °F (60 °C)*
Smoked ham, fully cooked, canned, boneless
3 to 10 lb 1.4–4.5 kg
15–20 min/lb 33–44 min/kg
140 °F (60 °C)*
Smoked ham, fully cooked, arm picnic shoulder, boneless
5 to 8 lb 2.3–3.6 kg
25–30 min/lb 55–66 min/kg
140 °F (60 °C)*
Smoked ham, cook-before-eating, whole, bone in
10 to 16 lb 4.5–7.3 kg
18–20 min/lb 40–44 min/kg
145 °F (62.8 °C), rest 3 min
Smoked ham, cook-before-eating, half, bone in
5 to 8 lb 2.3–3.6 kg
22–25 min/lb 49–55 min/kg
145 °F (62.8 °C), rest 3 min
Smoked ham, cook-before-eating, shank or butt portion, bone in
3 to 4 lb 1.4–1.8 kg
35–40 min/lb 77–88 min/kg
145 °F (62.8 °C), rest 3 min
Smoked ham, cook-before-eating, arm picnic shoulder, boneless
5 to 8 lb 2.3–3.6 kg
30–35 min/lb 66–77 min/kg
145 °F (62.8 °C), rest 3 min
Smoked ham, cook-before-eating, shoulder roll (butt), boneless
2 to 4 lb 0.9–1.8 kg
35–40 min/lb 77–88 min/kg
145 °F (62.8 °C), rest 3 min
Fresh ham, uncooked, whole leg, bone in
12 to 16 lb 5.4–7.3 kg
22–26 min/lb 49–57 min/kg
145 °F (62.8 °C), rest 3 min
Fresh ham, uncooked, whole leg, boneless
10 to 14 lb 4.5–6.4 kg
24–28 min/lb 53–62 min/kg
145 °F (62.8 °C), rest 3 min
Fresh ham, uncooked, half, bone in
5 to 8 lb 2.3–3.6 kg
35–40 min/lb 77–88 min/kg
145 °F (62.8 °C), rest 3 min
* Reheat to 140 °F (60 °C) if the ham was packaged in a USDA-inspected plant, otherwise to 165 °F (73.9 °C). Whole and half bone-in hams appear in both FSIS charts, the ham timetable and the holiday roasting chart, with neighbouring weights; where the minutes per pound agree the weights are joined, and where they differ both are listed.
Beef, pork and lamb
FSIS’s holiday roasting chart puts most roasts at 325 °F, tenderloins at 425 °F for a total time, and a crown roast of lamb at 375 °F. Every raw beef, pork and lamb roast is safe at 145 °F (62.8 °C), measured before it comes out of the oven, followed by at least 3 minutes’ rest. FSIS adds that you may cook meat to a higher temperature if you prefer it more done.
Cut
Weight
Oven
Time
Target
Beef, rib roast, bone in
4 to 8 lb 1.8–3.6 kg
325 °F (163 °C)
23–30 min/lb 51–66 min/kg
145 °F (62.8 °C), rest 3 min
Beef, rib roast, boneless
4 lb 1.8 kg
325 °F (163 °C)
39–43 min/lb 86–95 min/kg
145 °F (62.8 °C), rest 3 min
Beef, eye round roast
2 to 3 lb 0.9–1.4 kg
325 °F (163 °C)
20–22 min/lb 44–49 min/kg
145 °F (62.8 °C), rest 3 min
Beef, tenderloin roast, whole
4 to 6 lb 1.8–2.7 kg
425 °F (218 °C)
45–60 min total
145 °F (62.8 °C), rest 3 min
Beef, tenderloin roast, half
2 to 3 lb 0.9–1.4 kg
425 °F (218 °C)
35–45 min total
145 °F (62.8 °C), rest 3 min
Pork, loin roast, bone in
3 to 5 lb 1.4–2.3 kg
325 °F (163 °C)
20–25 min/lb 44–55 min/kg
145 °F (62.8 °C), rest 3 min
Pork, loin roast, boneless
2 to 4 lb 0.9–1.8 kg
325 °F (163 °C)
23–33 min/lb 51–73 min/kg
145 °F (62.8 °C), rest 3 min
Pork, crown roast
6 to 10 lb 2.7–4.5 kg
325 °F (163 °C)
20–25 min/lb 44–55 min/kg
145 °F (62.8 °C), rest 3 min
Pork, tenderloin
½ to 1½ lb 0.2–0.7 kg
425 °F (218 °C)
20–30 min total
145 °F (62.8 °C), rest 3 min
Lamb, leg, bone in
5 to 9 lb 2.3–4.1 kg
325 °F (163 °C)
20–26 min/lb 44–57 min/kg
145 °F (62.8 °C), rest 3 min
Lamb, leg, boneless
4 to 7 lb 1.8–3.2 kg
325 °F (163 °C)
20–26 min/lb 44–57 min/kg
145 °F (62.8 °C), rest 3 min
Lamb, crown roast
3 to 4 lb 1.4–1.8 kg
375 °F (191 °C)
20–30 min/lb 44–66 min/kg
145 °F (62.8 °C), rest 3 min
The chart is approximate: FSIS describes it as compiled from various resources, for meal planning. Two things in it explain a lot. Boned and rolled cuts need more time per pound than bone-in ones, because heat takes longer to reach the middle of solid meat, which is why a boneless rib roast is 39 to 43 minutes per pound against 23 to 30 for bone-in. Tenderloins, roasted hotter at 425 °F, are timed as a total rather than per pound.
Worked examples
6 lb bone-in rib roast (prime rib): 23 to 30 minutes per pound is 138 to 180 minutes, 2 hours 18 minutes to 3 hours at 325 °F. In at 1:00 pm, start checking at 3:15 pm and have it out by 4:00 pm.
12 lb whole fully cooked ham: 15 to 18 minutes per pound is 3 hours to 3 hours 36 minutes to reach 140 °F.
8 lb spiral-cut ham: 10 to 18 minutes per pound is 1 hour 20 minutes to 2 hours 24 minutes. It is already cooked, so you are only warming it.
7 lb bone-in leg of lamb: 20 to 26 minutes per pound is 2 hours 20 minutes to 3 hours 2 minutes, to 145 °F.
5 lb boneless rib roast: FSIS only times a 4 lb boneless rib roast, so the calculator shows no time rather than stretching 39 to 43 minutes per pound to fit. Roast it at 325 °F and go by the thermometer.
Common mistakes
Stretching the per-pound rate. Each FSIS row covers a weight band, and FSIS gives no time outside it, so neither does the calculator.
Probing next to the bone. FSIS says to put the thermometer in the thickest part of the meat, away from bone, fat or gristle.
Mixing up the hams. A cook-before-eating ham that is only warmed through hasn’t reached the 145 °F it needs, and a fully cooked ham doesn’t need roasting at all. Read the label.
Warming every cooked ham to 140 °F. That figure is for hams packaged in a USDA-inspected plant. Any other cooked ham, and leftovers, go to 165 °F.
A low oven. FSIS doesn’t recommend roasting meat below 325 °F, because it can sit too long between 40 and 140 °F.
Carving straight away. FSIS asks for at least 3 minutes’ rest after a raw roast reaches 145 °F, “for safety and quality”.
At 325 °F: a whole, bone-in, fully cooked ham takes 15 to 18 minutes per pound to reach 140 °F; a whole cook-before-eating ham 18 to 20 minutes per pound to reach 145 °F; a spiral-cut ham 10 to 18 minutes per pound; and a whole fresh ham, bone in, 22 to 26 minutes per pound to 145 °F.
How long does prime rib take per pound?
FSIS gives 23 to 30 minutes per pound at 325 °F for a bone-in rib roast of 4 to 8 lb, and 39 to 43 minutes per pound for a 4 lb boneless one. It is safe at 145 °F (62.8 °C) after at least 3 minutes’ rest.
What temperature should a ham be heated to?
A fully cooked ham packaged in a USDA-inspected plant: 140 °F (60 °C). Any other cooked ham, and leftovers: 165 °F (73.9 °C). A fresh or cook-before-eating ham is raw and must reach 145 °F (62.8 °C), then rest at least 3 minutes.
Do I need to cook a spiral-cut ham?
No: FSIS lists spiral-cut hams with the cooked hams, which can be eaten cold or reheated. To serve it warm, allow 10 to 18 minutes per pound at 325 °F for a 7 to 9 lb ham, to 140 °F if it was packaged in a USDA-inspected plant.
How long does cooked ham keep in the fridge?
FSIS gives 7 days for a whole store-wrapped cooked ham, 3 to 5 days for half hams, slices, spiral-cut hams and leftovers, and the “use-by” date for a dated ham vacuum-sealed at the plant and still unopened.
Sources
Ham types, the ham timetable at 325 °F, reheating to 140 °F or 165 °F, country ham and storage times: USDA FSIS, Hams and Food Safety (last updated 15 January 2025).