Work out how much shrimp to buy for a group and roughly how many that is by size.
Usage Tip
Buy shell-on for more flavour, or peeled to save prep time.
How Much Shrimp Per Person?
For a main course, plan on 6–8 oz of shrimp per person; as an appetizer, 3–4 oz. At a seafood boil where shrimp share the pot with sausage, corn, and potatoes, half a pound per person is generous. Remember these are shell-on weights – peeled shrimp go further because you are not paying for shell.
raw to buy = edible needed ÷ yield %
The calculator above totals it for any shellfish, serving style, and guest count, and tells you how much to buy.
Shellfish Portion Guide
| Shellfish | Appetizer | Main course |
|---|---|---|
| Shrimp | 3–4 oz | 6–8 oz |
| Crab legs | 1/2 lb | 1–1.5 lb |
| Lobster tail | 1 tail | 1–2 tails |
| Mussels | 1/2 lb | 1 lb |
| Clams | 6–12 pieces | 1–2 dozen |
| Scallops | 3–4 oz | 5–6 oz |
| Oysters | 3–6 pieces | 6 pieces |
Serve a little more for big appetites, less at a buffet where guests are sampling several proteins.
Shrimp Count-Size Guide
Shrimp are sized by how many it takes to make a pound – the “count.” A lower count means bigger shrimp. “16/20” means 16–20 shrimp per pound.
| Count | Size name | Shrimp per lb |
|---|---|---|
| 16/20 | Jumbo | 16–20 |
| 21/25 | Extra large | 21–25 |
| 26/30 | Large | 26–30 |
| 31/40 | Medium-large | 31–40 |
| 41/50 | Medium | 41–50 |
Shell-On vs Peeled Shrimp Yield
Shell-on shrimp yield about 50% peeled meat – head, shell, and tail are the rest. So 2 lb of shell-on shrimp gives roughly 1 lb of edible meat. Peeled shrimp cost more per pound but are nearly all edible, so for the same amount on the plate you buy about half the weight. Buy shell-on for boils and flavor; peeled for convenience and exact portions.
Crab Leg Portion Guide
Crab legs are mostly shell – figure 1–1.5 lb per person for a main course, half a pound as an appetizer. At about 45% meat yield, 1.5 lb of legs gives roughly 10–11 oz of picked meat. Snow and king crab legs run similar; king has a slightly higher meat ratio.
Lobster Portion Guide
Plan 1–2 lobster tails per person, or one 1.25–1.5 lb whole lobster each for a main course. Lobster tails yield more usable meat than whole lobster – roughly half the tail weight is meat. For a richer menu with several courses, one tail per guest is plenty.
Seafood Boil Planning
A seafood boil is generous, communal, and easy to under-buy. Per person, plan about 1/2 lb shrimp, 1/2–3/4 lb crab or 1 lobster tail, 1/2 lb mussels or clams, plus sides (1 ear of corn, a few small potatoes, a sausage link). Mix two or three proteins so no single one has to carry the meal.
Cooked vs Raw Shrimp
Shrimp shrink about 20–25% when cooked as moisture cooks off. If a recipe calls for cooked weight, buy a bit more raw to compensate. Already-cooked shrimp (often sold frozen) save a step but cost more and can overcook easily on reheating. The calculator can show the cooked/peeled equivalent of what you buy.
Yield Loss Chart
| Shellfish | Edible yield |
|---|---|
| Shrimp (shell-on) | ~50% |
| Shrimp (peeled) | ~95–100% |
| Crab legs | ~40–50% |
| Lobster tail | ~50–55% |
| Scallops | ~90–100% |
| Mussels | ~25–30% |
| Clams | ~25–30% |
| Oysters | ~10–15% |
Thawing & Cooking Notes
Thaw frozen shellfish in the fridge overnight or in a sealed bag under cold water, changing the water every 30 minutes – never at room temperature. Shrimp cook in 2–3 minutes and are done when pink and curled; mussels and clams are done when their shells open (discard any that stay shut). See the linked thawing and cooking calculators for exact times.
Food Safety & Allergies
- Keep shellfish cold until cooking and cook within a day or two of thawing.
- Discard mussels or clams that do not open when cooked, and any that are cracked or stay open when raw and tapped.
- Cook shellfish thoroughly unless using a trusted raw bar source for oysters.
- Allergy reminder: shellfish is a major allergen – check with guests and avoid cross-contact when serving a crowd.
Frequently Asked Questions
How much shrimp do I need per person?
6–8 oz shell-on for a main course, 3–4 oz as an appetizer, about 1/2 lb at a seafood boil.
What does shrimp count size mean?
It is how many shrimp make a pound – 21/25 means 21–25 per pound. Lower numbers are bigger shrimp.
How much seafood for a seafood boil?
Per person, roughly 1/2 lb shrimp plus 1/2–3/4 lb crab or a lobster tail and 1/2 lb mussels or clams, plus sides. Mix proteins and round up.
How many crab legs per person?
1–1.5 lb for a main course, 1/2 lb as an appetizer – they are mostly shell, so buy generously.
Shell-on or peeled shrimp – how much do I buy?
Shell-on yields about 50% meat, so buy roughly double the edible weight you want. Peeled is nearly all edible.
How much do shrimp shrink when cooked?
About 20–25% by weight. Buy a little extra if your recipe specifies cooked weight.
Related Seafood Calculators
Seafood purchasing note: portions vary by appetite, menu, and how many other dishes are served, and shell-on yields vary by species, size, and season. Treat these as planning estimates, add a buffer for events, and confirm with your supplier. Shellfish is a common allergen – this is general guidance, not food-safety or food-cost certification.