How Much Roast Lamb per Person for a Big Group

How Many Pounds of Roast Lamb per Person for a Large Group – Plus an Exact Table Of How Many Pounds Of Lamb To Buy

Cooking Roast lamb and feeding a crowd is often challenging when you consider meat shrinkage after cooking. Understanding this will let you buy the correct amount from your local butcher or supermarket. It is even more important as a lot of lamb is imported as frozen, so you can not get it cut to size as easily as other meats.

A great resource that will help you plan and cook a large batch of roasted lamb for a crowd.

Plus we have a handy table and chart of the exact amounts you need to feed groups between 5, 10, 20, 30, 50, 70, and 100 people.

Plus we cover things like what sides pair well with roast lamb.

The best way to make a good meal is to have the right ingredients and cook them properly. We’ve got you covered on that front, too. 

You’ll also learn about different types of lamb roasts including boneless, racks, and bone-in.

You may also be interested in some other meat portions

Finally, here are some suggestions for types of events and numbers of attendees.

How to Calculate How Much Lamb Roast Per Person To Feed A Crowd

You calculate how much roast lamb per person by taking into account

  • What kind of meal
  • The length of time for which the party or event lasts
  • Plus knowing how much does roasted lamb shrink when cooked

People sometimes don’t realize just how much meat they really consume, especially when eating succulent roast lamb. So having an extra helping isn’t always bad.

We are also going to assume in our Lamb Roast Handy Table below that it is the only meat on our menu so in our calculations of how much roast lamb do we feed each person is based on this.

How Much Roast Lamb per Person at A Bbq
How Much Roast Lamb per Person at A BBQ – People can eat more at a BBQ so serve a minimum of 6oz and maybe as much as 8 0z for each person

Know Your Guests?

Know your guests when you are serving the roast lamb because everybody likes crackling and if you aren’t careful you will quickly run out of that of the road. Also, guests may vary in their appetite levels. You might want to rethink serving large portions at your family gathering if they tend to be heavy eaters. If it’s food for a sporting event, then everyone will be starving by the end of the game. Remember that kids eat smaller portions than grownups. So take that into consideration.

What is the Shrinkage of Roast Lamb

Roast Lamb cuts will typically shrink around 30-35%.

Why does Roast Lamb Shrink?

Lamb Roast shrinks because of

  • loss of moisture
  • fat trimming 
  • bone also results in a lesser yield – e.g Roast lamb rack will  have bone in

What’s leftover to serve is referred to as the yield.

What Is the Yield of Roast Lamb? 

For boneless lamb roast use an average of 35% weight loss due to cooking. For bone-in cuts it can be as high as 45% or more.

How Many Pounds of Roast lamb per Person for A Crowd

How much Lamb Roast per person is needed to serve to feed a large group.  See our handy chart below where all the work has been done for you and the exact amounts of roast lamb that you need to serve. Then we have also calculated the amount of uncooked or raw roast lamb you need to purchase so there is enough meat for everybody.

What is the serving size for lamb roast?

For a Large Family Dinner or Big Group BBQ the serving size of lamb is 6oz of roast per person

A Handy Table for 10-100 People For How Much Lamb To Serve and Buy

This table assumes that lamb is the only protein being served

How Much Roast Lamb Do you need to feed 10 people

For 10 People you will need 4 lbs of cooked Roast lamb – this gives seconds for some guests

How Many Pounds of Uncooked lamb Do You Need for 10 People

You need to buy 6 lbs of raw lamb


How Much Roast lamb Per Person Do you need for 20 people

For 20 People you will need 8 lbs of cooked Roast lamb

How Many Pounds of Uncooked lamb Do You Need for 20 Guests

You need to buy 12 lbs of raw lamb

How much Lamb should I order for a BBQ?
How much Lamb should I order for a BBQ?

How Much Roast lamb Per Person Do you need for 30 people

For 30 People you will need 12 lbs of cooked Roast lamb

How Many Pounds of Uncooked lamb Do You Need for 30 People

You need to buy 18 lbs of raw lamb for 30 people


How Much Roast lamb Do you need for 50 guests

For 50 People you will need 20 lbs of cooked Roast lamb

How Many Pounds of Uncooked lamb Do You Need for 50 People

You need to buy 30 lbs of raw lamb for 50 people


How Many Pounds of Roast lamb Do you need for 70 People

For 70 People you will need 28 lbs of cooked Roast lamb

How Many Pounds of Uncooked lamb Do You Need for 70 People

You need to buy 42 lbs of raw lamb for 70 people


How Many Pounds of  Roast lamb Do you need for a crowd of 100

For 100 People you will need 40 lbs of cooked Roast lamb

How Many Pounds of Uncooked lamb Do You Need for 100 People

You need to buy 60 lbs of raw lamb for 100 people


How many people will 2kg lamb serve?
How many people will 2kg lamb serve? – approximately 6 people

Here are some scaling factors for different big events that give you some adjustment factors for a lamb roast.

Sit Down Dinner Parties  –  increase quantities by 15% if seconds are to be available. Serving another meat dish in addition then you can decrease the quantity by 40%.

Buffet-style events increase the serving sizes by 25%. People always put more meat on their own plates.

How Do I  Keep Roast lamb Warm When Cooking For a Large Group – See How To Keep Food Warm for a crowd.

How To Store Roast lamb Leftovers

You can use them for breakfast tomorrow morning; they’re great cold too in sandwiches.

If you’re left with some roasted lamb after dinner one night, how do you prevent it from going bad?

Leftover roast lamb can be kept in the fridge for three days. of course, it must be kept in an air-tight container. It also freezes well.

You can freeze leftover roasted lamb for up to three months after roasting.

How Many Side Dishes Are Needed For Lamb Roast

If you’re roasting a whole leg of lamb, you’ll probably want three sides.

What Foods Pair Well With Roast Lamb

Roasting lamb is one of the best ways to enjoy this meat. The flavor is incredible and it pairs well with many different foods. However, when roasting lamb, there are certain food items that work well with it. Here is a list of some ideas.

1. Roasted potatoes

When cooking lamb, potatoes are always a great addition. They go perfectly with the flavors of the meat and they pair well with the richness of the meat.

See how many roast potatoes to serve per person at a summer BBQ

2. Green beans

Green beans are a wonderful side dish to roast lamb. They have a mild taste and they pair well with any type of meat.

3. Garlic

Garlic is a great ingredient to use when making roasted lamb. It adds a lot of flavor to the meat and it goes well with almost anything.

4. Mint

Mint is a delicious herb that goes well with lamb. It gives off a fresh and clean flavor that works well with the rich flavors of the meat.

5. Rosemary

Lamb and rosemary are a classic pairing that goes back centuries. It’s a combination that works so well together. The two ingredients complement each other perfectly.

I love lamb and rosemary together because they have such a wonderful flavor. They also pair well with other flavors like garlic, lemon, mint, oregano, thyme, basil, parsley, sage, chives, cilantro, dill, tarragon, fennel, and many others.

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