Costco King Crab Legs: How to Cook These Magnificent Beauties

Costco King Crab Legs

The king crab legs at Costco are amazing and if you are looking for something special for a holiday meal, a romantic dinner or just feel like splurging on yourself then these are absolutely perfect.

Costco King Crab Legs

This post will try to answer the most frequently asked questions about these crab legs and I will show you how I cook them on the grill.

Costco King Crab Legs: Everything You Need to Know About 

When I first saw these legs at the store I thought they looked beautiful but had no idea about what to do with them.  I checked around on Reddit and saw that a lot of other folks that were confused.

There are three types of King Crabs; Red, Blue and Golden.  The legs sold at Costco are Red King Crabs which is considered to have the best flavor of the three varieties.

How Much Do Crab Legs Cost?

King crab legs are currently selling for about $27 per pound if you are buying the thawed 2-3 pound portions so expect to pay about $60 for a package.  The costs drops to about $25 per pound if you buy the large, frozen ten pound box so that will set you back about $250.

These prices are for large legs that are 6/9 sized.  The numbering system for legs refers to how many legs would be needed to fill a ten pound box.

The largest legs I have seen are 4/7 and they are also available in the smaller sizes of 9/12 and 16/20.  While different sizes are available online, the only size that I have seen for sale inside a Costco store is 6/9.

In general, the larger the size the more expensive they are on a per pound basis.

Are the Legs Pre-Cooked?

Yes, the crab legs are pre-cooked.  The crabs are steamed at the dock as soon as the crabbing boats come in from the harvest.

Most people like to reheat the legs, either by steaming or grilling, but you can eat the meat cold.

10 Pound Box of King Crab Legs

I can’t tell you what is in every Costco but at my store in Baton Rouge you can buy a 10 pound box of frozen legs that are 6/9 sized.  There is not a significant per pound price difference between the thawed 2-3 pound portions and the frozen 10 pound portions.

I prefer to buy the 2-3 pound packages so I don’t have to thaw the legs and because I can see exactly what I am buying.  You can’t really see what the frozen legs look like since they are mostly obscured by the box.
10 pound box of king crab legs

You can order 10 pound boxes of crab legs from Costco online and have them delivered but you need to be careful about your order.  There are multiple sizes available online but they are all smaller than the 6/9 legs that are in the store.

The largest ones Costco offers online are 9/12 and the price jumps to $40/pound for these smaller legs to cover shipping.

How We Cook King Crab Legs

Since the crab is already cooked all we are really going to do is heat the legs up on the grill while basting them with some butter.

Start by breaking the legs into sections by twisting them at the joints.  This will help the legs fit onto the grill and allows you to cook the smaller and larger pieces for different periods of time.

two pounds of crab legs

After the legs have been broken down I use a pair of scissors to cut out sections of the shell so I can baste melted butter directly onto the meat.

Open the shell

I arrange the legs on my Weber Q1200 gas grill and cook them on High.  The legs are grilled for about ten minutes and get basted with melted butter a couple of times.

I will take the smaller pieces off the grill once I see that they are steaming but leave the larger knuckles on for a few more minutes to make sure they have the chance to heat all of the way through.

King Crab Legs on Weber Q

Once the legs are off the grill then it really is every man for themselves as we tear into these beauties. 

This batch never even made it back to the kitchen.  We just stood by the grill, tore open the shells and dunked the spectacular meat into melted butter before devouring.

The crab is salty and EXTREMELY rich.  A few lemon wedges would have been nice to help cut through the richness but we managed just fine without.

Serve Crab with Butter

This crab is simply amazing.

Due to the richness I don’t think I would want to eat this everyday which is probably a good thing given its price.  However, the crab is so delicious that I will be going back for another order soon!

Serve Crab with Butter

Costco King Crab Legs

King Crab Legs are broken into sections and heated through before being served with melted butter and lemon.
Prep Time 15 minutes
Cook Time 15 minutes
Total Time 30 minutes
Course Main Course
Cuisine American
Calories 300 kcal


  • 3 lbs King Crab Legs
  • 3 tbsp melted butter
  • 1 lemon cut into wedges


  • Remove the crab legs from the packaging and break into sections at the joints.
  • Place the crab on a hot grill and heat until warm (10-15 minutes). You can also use a steamer or bake in a 350F oven.
  • Use scissors to open up the shell on the legs, remove the meat and serve with melted butter and lemon wedges.


King Crab legs that you find in grocery stores are already fully cooked.  This recipe is simply warming the crab up before serving with butter.  Some people will skip the warming step and will serve the crab meat cold as crab salad.
Keyword King Crab Legs

FYI…for a more affordable seafood treat, check out the Costco lobster tails!  They cost the same as King Crab on a per pound basis but come in a smaller package so the overall cost is lower.