Blue Fin Tuna Size Comparison: Just How Big Do They Get?

Written by Katie Melynn Wood
Updated: July 5, 2023
© lunamarina/
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One of the largest fish in the ocean and the largest species of tuna, bluefin tuna are amazing ocean predators. They are sought after for dishes like sushi and sashimi. These animals live all over the world, but some areas are known for particularly large specimens.

Bluefin tuna are typically between 6 and 10 feet long and weigh between 500 and 1500 pounds. Because they are so large, special equipment is needed to bring in one of these powerful fish. Often, teams of fishermen reel the large fish in together over many hours or even days.

How Big Are Blue Fin Tuna When They Are Born?

When they hatch, these tuna are ready to start eating right away. After just one week, they are around a quarter of an inch long and just keep growing from there. There are two main spawning areas for bluefin tuna. In the Atlantic, the eastern group tends to spawn in the western part of the Mediterranean Sea. The western stock spawns in the Gulf of Mexico.

They will eat other tuna babies nearby, which is one reason why their survival rate is so low. The time period after they are newly hatched is one of the most vulnerable times for these fish. Other predatory fish, including other species of tuna, will eat them. Even though some are eaten as babies, others feed their own appetites and grow quickly. They eat herring, mackerel, and eels. As they grow larger, bluefin tuna begin to school with others of a similar age and size. They are powerful predators with muscles and bodies that help them swim fast through the water.

Most research and tracking shows that bluefin tuna mature quickly. They do get larger as they grow. Most reach full maturity well before they are even 15 years old. The eastern stock typically matures a bit earlier than the western stock, up to one or two years faster even.

Bluefish tuna swims in the ocean with a fishing net in the background
Bluefish tuna can grow to be as large as a cow, polar bear, or car!

©Alexius Sutandio/

The Largest Blue Fin Tuna Ever Recorded

In 1979, a fisherman caught a bluefin tuna weighing 1,496 pounds. The massive fish was caught by Ken Fraser in Nova Scotia, Canada. The area is known for bluefin tuna fishing. This impressive catch cemented its reputation as great fishing for all time. It is still one of the top places to go to catch these amazing fish and there are plenty of charter boats and tour companies that can guide you through a fishing expedition.

One tuna is a huge financial prize for commercial fishermen. It sells for at least $20 per pound, often much more. Considering how large these fish are, that’s a lot of fish in one catch. Fraser took just under an hour to reel in the 1,496-pound fish. He had to use specialized equipment capable of handling such large and powerful fish. If you want to go fishing for your own prize fish, make sure that you are ready for an exhausting physical fight if you get one on the line.

It can be hard to imagine 1,500 pounds of tuna moving swiftly through the water. Fortunately, we have plenty of helpful comparisons to put things in perspective.

Bluefin tuna versus cow

A cow weighs between 700 and 1,760 pounds, depending on the breed. Holstein cows are black and white, the iconic look of dairy cows. Mature Holsteins are around 1,500 pounds, the same weight as the largest tuna.

Bluefin tuna versus polar bear

Believe it or not, a bluefin tuna can actually be larger than an adult polar bear. These enormous arctic bears weigh up to 1,322 pounds at the largest. Polar bears are as long as many bluefin tuna. Both species can be over 6 or even 8 feet long.

Bluefin tuna versus a car

One of the lightest cars is the Toyota Carolla. The sedan is around 2,800 pounds. This is still almost twice the weight of even the largest tuna. The Mitsubishi Mirage, however, is around 1,900 pounds. While the care is still heavier, the gigantic fish is not far off from the small, compact vehicle.

Fastest Sea Animal: Atlantic Bluefin Tuna
The Atlantic bluefin tuna is one of the largest, fastest, and most gorgeously colored of all the world’s fishes.


Is a Blue Fin Tuna Bigger than a Yellowfin Tuna?

Yes, bluefin tuna are usually bigger than yellowfin tuna. Yellowfin tuna can grow up to 6 feet long and around 400 pounds. A mature bluefin tuna can grow to almost four times that size at its largest. These larger tuna can get up to 10 feet or longer and up to almost 1,500 pounds. Even small bluefin are around 500 pounds when they are fully grown. Of course, juvenile bluefin can be much smaller than mature yellowfin.

Both species live in the Atlantic and Pacific oceans and swim throughout the same areas. It’s possible that they would encounter each other quite frequently. In cooking, yellowfin tuna is less expensive than bluefin tuna. But it also lacks the same rich taste and color that make bluefin so desirable. It is also a firmer fish. Both are great options if you want to try a delicious tuna dish.

Is a Blue Fin Tuna Bigger than an Albacore Tuna?

Yes, bluefin tuna are bigger than Albacore tuna. Albacore usually top out at just under 100 pounds, a mere fraction of a typical bluefin. They grow up to around 4 feet long and are much leaner than the more muscular and larger bluefin.

Bluefin tuna have a darker pink/red color while Albacore tuna are light pink or almost white. Albacore tuna is generally used to produce canned tuna. It has a light, flaky texture and taste that make it work well in salads and sandwiches. Bluefin tuna, on the other hand, is much richer and fattier.

Fishing boat fishing for tuna fish in the Indian Ocean. Fishing operation
Fishing for bluefin tuna requires strong equipment and knowledge.

©Gema Alvarez Fernandez/

Fishing for Blue Fin Tuna

Bluefin tuna are considered endangered so there are a lot of rules when it comes to fishing for them. The World Wildlife Federation recommends that you only fish for bluefin tuna from stocks that are closely monitored to prevent major issues to the population from overfishing. If you don’t want to fish for bluefin tuna but still want to enjoy the fish in cooking, look for a sustainable and reputable place to purchase tuna from to ensure that it was caught responsibly.

If you want to try fishing for one of these amazing fish, it’s a good idea to work with a charter boat to have the best chance of catching and reeling in the powerful fish. The boat must have a special license, which allows everyone onboard to fish for bluefin tuna. Companies that arrange tours and charters are experienced not only with the equipment and fishing tips but also with the laws and licensing.

There are some regulations about where and when you can fish for bluefin tuna. You should avoid known spawning areas as it is illegal to target bluefin tuna in these regions. Overfishing was an issue for the bluefin tuna population in the past, which led to increased regulation and monitoring of the species. Now, there are quotas on the number of bluefin tuna that you can catch and keep. It varies by location and size of the tuna itself.

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About the Author

Katie is a freelance writer and teaching artist specializing in home, lifestyle, and family topics. Her work has appeared in At Ease Magazine, PEOPLE, and The Spruce, among others. When she is not writing, Katie teaches creative writing with the Apex Arts Magnet Program in Anne Arundel County, Maryland. You can follow Katie @katiemelynnwriter.

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