A Complete Guide to Shrimp Sizes

If you’ve ever shopped Sizzlefish or at a seafood counter, you’ve probably seen labels like “16/20” or “U10” and wondered what they actually mean. Understanding shrimp sizing is essential, not just for cooking, but also for getting the best value for your money. In this guide, we’ll explain how shrimp are sized, what the numbers mean, and how to choose the right shrimp for your needs.

What Do Shrimp Sizes Mean?

Shrimp are sized based on how many shrimp make up one pound. This is known as the “count per pound.” The smaller number will have bigger shrimp, and the larger number will have smaller shrimp. For example, 16/20 shrimp means there are between 16 and 20 shrimp in one pound, and 31/40 shrimp means there are between 31 and 40 shrimp per pound. So, the lower the count, the larger each shrimp will be.

What Does “U” Mean in Shrimp Sizing?

Sometimes you’ll see a size labeled with a “U,” such as U10 (Under 10). This means there are fewer than 10 shrimp per pound, making them some of the largest shrimp available. These are often called “super colossal” shrimp and are ideal for premium dishes or impressive presentations.

Common Shrimp Size Categories

There is no industry standard for shrimp sizing, but here’s a general breakdown of how we size our shrimp and what they’re typically called:

U10 – Super Colossal & U12 – Colossal

Shrimp Size: Super colossal shrimp are the largest shrimp in the market, with fewer than 10 shrimp per pound. Colossal shrimp follow closely with fewer than 12 shrimp per pound.

How long to cook: Since they are the largest shrimp, cooking them can take up to 15 minutes. They’re best suited for main dishes, grilling, or when you want a bold presentation.

16/20 – Jumbo

Shrimp Size: Jumbo shrimp average around 16-20 shrimp per one-pound bag.

How long to cook: Typically take 8–10 minutes to cook. Ideal for grilling, sautéing, or shrimp cocktails.

21/25 – Large

Shrimp Size: Large shrimp contain 21–25 shrimp per pound, offering a great balance between size and value.

How long to cook: Usually cook in 6–8 minutes. Perfect for pasta dishes, tacos, and stir-fries.

31/40 – Medium

Shrimp Size: Medium shrimp have 31–40 shrimp per pound, making them versatile and budget-friendly.

How long to cook: Cook in about 5–7 minutes. Great for fried rice, soups, salads, and mixed dishes.

41/50 – Small

Shrimp Size: Small shrimp include 41–50 shrimp per pound, making them ideal for recipes where shrimp are mixed throughout.

How long to cook: Cook quickly in 4–6 minutes. Best for salads, pasta, casseroles, and appetizers.

Keep in mind that naming conventions can vary slightly by seller, but the count per pound is always the most reliable indicator. Also, shrimp are very easy to overcook because they are so delicate. They turn dry and chewy if cooked too long. The key is to watch for the color and shape. They should be pink and opaque, not white. The shape should resemble a “C” when done. A tight “O” means they are overcooked. Simple methods like sautéing and grilling are best for cooking shrimp.

Why Shrimp Size Matters

Choosing the right shrimp size depends on how you plan to use them:

1. Cooking Style

• Grilling or grilling skewers: Larger shrimp (U10–16/20) hold up better and look more impressive.

• Pasta, stir-fry, or tacos: Medium to large shrimp (21/25–31/40) are versatile and cook quickly.

• Soups, salads, or fried rice: Smaller shrimp (41/50+) distribute evenly throughout the dish.

2. Cooking Time

Larger shrimp take longer to cook, while smaller shrimp cook very quickly. Overcooking can make shrimp rubbery, so size directly impacts timing.

3. Cost Efficiency

Larger shrimp usually cost more per pound. If presentation isn’t critical, smaller shrimp can be a more budget-friendly option without sacrificing flavor.

Fresh vs Frozen Shrimp Sizing

Shrimp are typically sized before freezing, so whether you buy fresh or frozen, the count per pound should remain consistent. However, frozen shrimp often offer better value and freshness, as they’re usually frozen shortly after being caught.

Why do shrimp shrink when cooked?

When cooking shrimp, the heat causes their muscle proteins to contract, which squeezes out water, causing them to shrink in size. Seafood and shrimp treated with preservatives will cause them to significantly shrink in size because the preservatives cause them to retain more water. Our seafood and shrimp are never treated with any preservatives, so you can expect to receive only pure, natural seafood.

Final Thoughts

Shrimp sizing may seem confusing at first, but once you understand that it’s all about count per pound, it becomes much easier to shop smart. Whether you’re preparing a gourmet meal or stocking your online store, knowing shrimp sizes helps you choose the right product every time.

Looking to buy high-quality shrimp? Explore our selection and find the perfect size for your next dish.