Saltwater Fish Measurement Guidelines


Most finfish size limit regulations of the Florida Fish and Wildlife Conservation Commission (FWC) use either Fork Length or Total Length.

These measurement methods provide a consistent, well defined measurement technique. These methods encourage angler compliance with fishery management regulations.

Using a flexible measuring tape and following the contour of the fish will result in an inaccurate measurement that is greater than the actual straight line measurement.  

I want to measure...

Total Length
Fork Length
Lower Jaw  Fork Length
Stone Crab
Spiny Lobster

Total Length Measurement

Total Length is now measured from the most forward point of the head, with the mouth closed, to the farthest tip of the tail with the tail compressed or squeezed, while the fish is lying on its side.

How to measure a Red Drum fish

How to measure a Mutton Snapper

How to measure a Yellowmouth Grouper

Total Length Species Include:

Snapper Family Tripletail
Grouper Family Bonefish
Red Drum Sheepshead
Black Drum Flounder
Snook Several ornamentals
Spotted Seatrout (Angelfish, etc.)

Fork Length Measurement

Fish regulated by fork length are measured from the tip of the jaw or tip of the snout with closed mouth to the center of the fork in the tail.

How to measure a Spanish Mackerel

How to measure a Hogfish

How to measure a Gray Triggerfish

Fork Length Species Include:

Amberjacks Bluefish
Rudderfish King Mackerel
Hog Fish Spanish Mackerel
Dolphin Permit
Cobia Pompano
Mullet African Pompano

Lower Jaw Fork Length Measurement (Billfishes)

Fish regulated by lower jaw fork length are measured in a straight line from the anterior most part of the lower jaw (tip of the lower jaw) to the fork in the tail.

How to measure a Billfish

Lower Jaw Fork Length Species Include:

Sailfish Blue Marlin
White Marlin

How to Measure Stone Crab and Spiny Lobster

Stone Crab Measurement

Stone Crab claws must measure at least 2 3/4-inches in length measured by a straight line from the elbow to the tip of the lower immovable finger. The forearm (propodus) shall be deemed to be the largest section of the claw assembly that has both a moveable and immovable finger and is located farthest from the body of the crab.

How to measure a Stone Crab

Spiny Lobster Measurement

Spiny Lobster must have a minimum carapace length of greater than 3-inches and the measurement must take place in the water. The carapace is measured beginning at the forward edge between the rostral horns, excluding any soft tissue, and proceeding along the middle to the rear edge of the carapace.

How to measure a Lobster

For more information please visit the Fish Length Measurement FAQs.

FWC Facts:
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Learn More at AskFWC