How long to cook bone in leg of lamb

When it comes to showstopping roasts, main dishes featuring turkey, beef, or pork might be your first thought. If that's you, we're here to make a case for a leg of lamb. The juicy, tender cut of meat is served in Middle Eastern cuisines year-round, but it makes quite a stunning holiday feast.

It may seem a bit overwhelming to attempt to cook lamb for the first time. But we promise leg of lamb is an easy cut of meat that allows for even roasting and tons of flavor. Our Test Kitchen is here to teach you how to cook leg of lamb to juicy perfection. We also include the proper temperature to cook a leg of lamb and what temperature to follow for your preferred preparation (medium or medium-rare). You'll have an impressive roast to display on the dinner table.

How long to cook bone in leg of lamb
How long to cook bone in leg of lamb

Blaine Moats

How to Cook Leg of Lamb

Because lamb leg is a tender cut, marinating isn't necessary. (If you do so, be sure not to marinate for more than three hours.) For this guide, we'll refer to our roasted leg of lamb recipe seasoned with citrus, herbs, and garlic.

Step 1: Prep Lamb and Season

Take leg of lamb out of refrigerator an hour before cooking and allow it to reach room temperature. Preheat your oven to 325°F (low and slow is the key for a juicy, flavorful leg of lamb). Cut ½-inch-wide slits about 1-inch deep into the leg of lamb. Drizzle with lemon juice, then sprinkle the herb mixture (we like parsley and mint or basil) and seasonings over meat. Insert slivers of garlic from 1 to 2 cloves into the slits cut into the leg of lamb.

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Step 2: Roast Leg of Lamb

Place meat on a rack in a shallow roasting pan ($15, Walmart). Roast the leg of lamb for at least 2 hours (see chart below for exact cooking times). For the juiciest results, we prefer cooking a leg of lamb to a medium rare (145°F) or medium (160°F) internal temperature.

Step 3: Rest and Serve

Remove leg of lamb from the oven, cover it loosely with foil, and allow it to rest for at least 15 minutes before carving.

Test Kitchen Tip: To carve leg of lamb, turn meat so the bone is parallel to the cutting board. Slice through the bottom of the meat with your knife parallel to the bone, angling straight down.

How Long to Cook Leg of Lamb

Follow these guidelines for how long to cook leg of lamb to your desired wellness. Use the following chart and roast leg of lamb until the thermometer registers the temperature listed under "Doneness." The meat's temperature will rise to the standard for medium rare (145°F) or medium (160°F) during the time it stands resting after taking out of the oven (see resting step) above.

LambWeightRoasting TimeDonenessBoneless leg of lamb4 to 5 lb.

5 to 6 lb.

1¾ to 2¼ hours
2 to 2½ hours
1¾ to 2½ hours
2½ to 3 hours135°F medium rare
150°F medium
135°F medium rare
150°F mediumLeg of Lamb (with bone)5 to 7 lb.

7 to 8 lb.

1¾ to 2½ hours
2¼ to 2¾ hours
2¼ to 2¾ hours
2½ to 3 hours135°F medium rare
150°F medium
135°F medium rare
150°F mediumLeg of lamb, shank half
(with bone)3 to 4 lb.1¾ to 2¼ hours
2 to 2½ hours135°F medium rare
150°F mediumLeg of lamb, sirloin half3 to 4 lb.1½ to 2 hours
1¾ to 2¼ hours135°F medium rare
150°F medium

How Long to Cook Leg of Lamb Per Pound

How long to cook bone in leg of lamb
How long to cook bone in leg of lamb

Karla Conrad

Depending on the size of the lamb leg, time may vary slightly—frequently check with a meat thermometer ($22, Target) while roasting to avoid overdoing it. If you have a size different than listed in the chart above, use these times as a guide.

  • Rare: 125°F (about 15 minutes per pound)
  • Medium-Rare: 130°F to 135°F (about 20 minutes per pound)
  • Medium: 135°FF to 140°F (about 25 minutes per pound)
  • Well-Done: 155°FF to 165°FF (about 30 minutes per pound)

Test Kitchen Tip: Freeze lamb in slices wrapped in foil. To warm later, place foil-wrapped slices in a 350°F oven.

How to Grill Leg of Lamb

Grill-roasting leg of lamb adds another dimension of flavor that is truly delicious. We recommend grilling leg of lamb using indirect heat to prevent the meat from cooking too fast on the outside before getting to the proper temperature. Use your favorite meat marinade, prep using the steps above, and get cooking by following these times to achieve your favorite leg of lamb temperature.

Boneless leg of lamb roast3 to 4 lb.

4 to 6 lb.

1½ to 2¼ hours
1¾ to 2½ hours
1¾ to 2½ hours
2 to 2¾ hours135°F medium rare
150°F medium
135°F medium rare
150°F mediumLeg of lamb (with bone)5 to 7 lb.1½ to 2 hours
1¾ to 2¼ hours135°F medium rare
150°F medium

Buying Leg of Lamb

How long to cook bone in leg of lamb
How long to cook bone in leg of lamb

Andy Lyons

If you prefer a boneless leg of lamb, purchase without the shank attached. Bones often give the meat more flavor but make carving trickier.

How to Cook Leg of Lamb for a Mouthwatering Holiday Feast

If you're excited about cooking a leg of lamb and need more recipe inspiration, we recommend our honey-rosemary roast lamb with potatoes and green beans. Feel free to use our BH&G custom roasting guide for all your holiday cooking needs.

How long should I cook a leg of lamb for?

Lamb should be roasted 20 mins per 450g/lb, plus an extra 20 mins. Weigh meat prior to roasting to determine cooking times. Cook at 220C/200C fan for the first 20 mins and then 190C/170C fan for the remaining time. Rest lamb before carving.

What temperature do you cook a bone

Best Temperatures to Cook It Here are the best temperatures to cook: For a 7-9 lb. leg of lamb at a medium internal temperature of 135° F <-> Cook at 350° for 15-20 minutes per pound. For fall off the bone internal temperature of 203° to 205° <-> Cook at 325° for 45-50 minutes per pound.

How long does a leg of lamb take to cook per kilo?

Season the meat all over with salt and pepper, then rub the lamb all over with the olive oil. Transfer to a roasting tin, sat on the onion slices. Roast for 20 mins. Lower the oven to 190C/170C fan/gas 5 and cook for another 15-20 mins per 500g (1 hr – 1 hr 20 mins for 2kg leg) depending on how pink you like your lamb.