Saltwater Fish Measurement Guidelines


Most finfish size limit regulations use either Fork Length or Total Length.

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

Do not use a flexible measuring tape. This type of measuring device will cause you to follow the contour of the fish and will result in an inaccurate measurement that is greater than the 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 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.




Total Length species include but are not limited to:

Snappers Tripletail
Groupers 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.




Fork Length species include but are not limited to:

Amberjacks Bluefish
Rudderfish King mackerel
Hogfish 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.


Lower Jaw Fork Length species include but are not limited to:

Sailfish Blue marlin
White marlin

How do I measure fish that have ragged-edge type tail filaments, such as scamp, yellowmouth grouper, or black sea bass?

For fish that have "ragged-edge" type filaments, these "pieces" of the tail should be included in the measurement of total length and measured to the "farthest tip of the tail" in the definition for total length.

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) is 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.


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.


History of Finfish Measurement in Florida

The state of Florida has wrestled with how to measure saltwater finfish since 1925. In 1925 the Legislature first enacted length measurements for marine finfish. Many different methods have been used over the years (1925-1973) including: tip of nose to fork of tail, tip of nose to tip of tail, tip of nose to end of tail, and tip of nose to rear center edge of tail. At any one time, one or all of these definitions were used. In the late 1980s, both a total length and a fork length size limit were listed in rule for some species. By the mid 1990s, only one measure was chosen for most species primarily based on the way federal regulations specified how the species should be measured. In 2006, the FWC clarified the definition of total length as having a pinched tail and closed mouth. Prior to that, FWC rules did not consistently state how to obtain total length, leaving this measurement open to interpretation by anglers and law enforcement officers. 


FWC Facts:
Did you know tiny little mosquitofish are put into drainage ditches and ponds to eat mosquito larvae?

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