This page offers a variety of information relating to seafood sizes, weights, units of measure, and yield. In many cases, seafood sizes are not standard and will vary locally. All information is approximate.
Hard Clams – Quahogs
Weight per pound and hinge size (thickness of clam measured at hinge) below are approximate:
Chowder .5 – 1.25 pounds each 2 + inches 200-250 per bushel
Cherrystone 3-4 per pound 2 inch
Topneck 5-7 per pound 1 1/2 inch
Middleneck 7-9 per pound 1 1/4 inch
Littleneck 10-13 per pound 1 inch
One bushel of quahog clams yields approximately 8 pounds of meats (with liquor).
One bushel of soft-shelled clams yields approximately 10 pounds of meats (with liquor).
Shucked Size – Number of oysters in a pint
Extra Large or Counts – less than 20
Large or Extra Select 26
Medium or Select – 26 – 38
Small or Standard – 38 – 63
Very Small – more than 63
Oysters in the Shell
Oyster farms often market their half-shell oysters at over 2.5-inches from hinge to bill; 3 inches is usually considered to be the normal size for half-shell oysters.
One bushel of oysters weighs approximately 45 to 60 pounds and contains between 100 and 150 oysters. A bushel of oysters yields approximately 7 pounds of meats (with liquor). A peck of oysters is 1/4 bushel.
Sea scallops and bay scallops are sorted according to size. Counts are expressed as a range. For example, 10/20 means that 1 pound of product contains 10 to 20 scallops. The smaller the size, the higher the count.
Large sea scallops are sometimes designated by the letter U, which stands for “under” followed by a number. The smaller the number, the bigger the scallop.
Under or U-10 (10 or less scallop meats per pound)
10-20 (10 to 20 per pound)
One bushel of sea scallops yields approximately 3.5 pounds of meats (adductor muscle only).
Warm water shrimp are usually sold by count per pound. Counts are expressed as a range. For example, 10/25 means that 1 pound of product contains 10 to 25 shrimp. The smaller the size, the higher the counts.
Shrimp sizes are occasionally expressed in names rather than numbers, such as “colossal,” “jumbos,” and “extra large.”
These designations are not universally defined or regulated and are open to a wider range of variance than the count system,
The following is a rough comparison of number of shrimp per pound for each market name:
Jumbo – 8 to 10
Large – 10 to 25
Medium – 26 to 40
Small – 41 to 60
Fresh Southern Atlantic and Gulf Coast shrimp are sometimes sold in mixed sizes or heads on. Heads-on shrimp yield considerably less meat per pound than heads-off product.
A rule of thumb is 2 pounds of heads-off shrimp in their shells will yield about 1 1/4 pounds when peeled.
Allow about 3/4-1 lb pound of headless shrimp in the shell per person; if the shrimp are shelled, figure about 1/3 to 2/3 pound per person.
It takes about 3 pounds of fresh heads-on coldwater shrimp to produce 1 pound of cooked peeled shrimp.
The net weight of the American lobster meat depends on the size and condition of the lobsters. Soft shelled lobsters net a much lower yield of meat than hard shelled individuals. Typically, 5 – 6 pounds of soft-shell lobsters or 4 – 5 pounds of hard-shell lobsters will net 1 pound of meat.
Blue crabs are sold by the piece, dozen, or bushel. Retail markets or online specialty suppliers may sort crabs into size. Local suppliers and wholesale operations usually offer crabs by the bushel.
Sizes or grades of bushels include #1, #2 and #3. The three grades are not precisely defined and exact sizes of crabs in each grade vary with location and season.
Typically, a bushel of #1 crabs will contain about 60 – 70 crabs (enough to feed about 10 – 12 people). Seafood dealers often estimate the weight of 1 bushel of crabs at approximately 40 pounds; each wooden bushel basket of crabs with lid weighs approximately 45 pounds each.
Blue crabs reach shell widths of up to 9 inches; a typical individual is usually 5-6 inches from tip to tip. Although there is no official standard for blue crab sizes, they are sometimes marketed using the following market terms:
Colossal – 6 1/2 inches or more.
Jumbo – 6 to 6 1/2 inches.
Large – 5 1/2 to 6 inches.
Medium – 5 to 5 1/2 inches.
Small – 4 1/2 to 5 inches.
* measured from shell tip to tip.
Depending on size, blue crabs weigh from about 5 to 16 oz. each. A typical crab picker can extract about 2-3 ounces of meat from each pound of whole blue crabs. Another expression for yield of crab meat is about 14% of whole weight. Actual yields depend on the size and condition of crabs and experience of the crab picker.
Soft-shelled Blue Crabs
Soft-shelled blue crabs (soft crabs) are often marketed by approximate size*:
Hotel – 4.5 to 5 inches
Prime – 5 to 5.5 inches
Jumbo – 5.5 to 6 inches
Whale – greater than 6 inches
* measured from shell tip to tip.
Dungeness crabs typically weigh 2-3 pounds each. On average 2 pounds of Dungeness crabs (live weight) yields about .5 pounds of picked meat.
Jonah crab sizes are usually expressed by carapace (upper shell) width. A Jonah crab with a carapace width of 5 inches typically weighs 12-14 oz.; A 5.5 inch crab might weigh 15-16 oz.; A 5.75 inch crab could weigh in around 18-19 oz.
Stone crab claws are usually sold pre-cooked and graded based on weight:
medium (up to 3 ounces)
large (between 3 and 5 ounces)
jumbo (5 ounces and up)
It generally takes about a pound of stone crab claws to feed one person.
Sizes of fish vary greatly as does the ratio of whole live weight to net weight of fillets. Depending on a variety of factors, fish may be sold whole, gutted only, headed and gutted, as skin-on fillets, skinless fillets, steaks, loins or smaller pieces.
Some fish yield much higher ratios of edible meat than others. Species such as flounder are a good value in terms of final yield. A good fish monger can net as much as 60% of live weight as boneless skin on fillets from flounder.
Most species of tuna fish yield around 42 percent white meat and 12 percent red meat.
Fish oil weighs approximately 7.5 lb/gal.
Units of Measure
A bushel is a U.S. and imperial unit of dry volume, equivalent in each system to 4 pecks, 8 gallons, 32 quarts.
1 United States bushel = 2150.42 cubic inches;
1 Imperial bushel = 2219.36 cubic inches.