Tuna Weight Calculator: Estimate Fish Weight by Length

🐟 Tuna Weight Calculator

Estimate tuna weight from length & girth measurements — all major species, imperial & metric

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📝 Measurement Inputs
🐟 Tuna Weight Estimate
📊 Tuna Species Max Weights
1,496 lb
Atlantic Bluefin Record
450 lb
Yellowfin Record
435 lb
Bigeye Record
88 lb
Albacore Record
76 lb
Skipjack Record
49 lb
Blackfin Record
105 lb
Longtail Record
446 lb
Pacific Bluefin Record
📋 Species Weight Formula Reference
Species Formula Divisor Typical L:G Ratio Avg. Form Factor Max IGFA (lb)
Atlantic Bluefin8000.60Heavy / Robust1,496
Yellowfin (Ahi)8000.58Moderate450
Bigeye8000.60Heavy435
Albacore9000.55Slim88
Skipjack9000.55Slim76
Blackfin8500.57Moderate49
Longtail8500.56Moderate105
Pacific Bluefin8000.61Heavy / Robust446
📐 Fork Length vs. Estimated Weight (Bluefin — Average Girth)
Fork Length (in) Fork Length (cm) Est. Weight (lb) Est. Weight (kg) Class
24618–123.6–5.4School
369125–4011–18School
4812260–9027–41Medium
60152120–16054–73Large
72183220–300100–136Giant
84213380–500172–227Giant
96244600–800272–363Trophy
110279900–1200408–544Trophy
🎯 Recommended Tackle by Estimated Weight
Est. Fish Weight Rod Class Line Class (lb) Hook Size Leader (lb)
Under 20 lb (9 kg)Light (10–20 lb)10–203/0–5/030–50
20–50 lb (9–23 kg)Medium (20–30 lb)20–305/0–7/050–80
50–100 lb (23–45 kg)Medium-Heavy (30 lb)30–507/0–9/080–130
100–200 lb (45–91 kg)Heavy (50–80 lb)50–809/0–11/0130–200
200–500 lb (91–227 kg)Heavy (80–130 lb)80–13011/0–13/0200–400
Over 500 lb (227 kg)IGFA 130 lb Class13013/0–16/0400–600
📏 Measuring Fork Length: Always measure from the tip of the jaw to the fork (deepest point) of the tail — not the tip of the tail. Fork length gives the most consistent weight estimates across all tuna species formulas.
📐 Girth Measurement Tip: Measure girth at the widest point of the fish, usually just behind the pectoral fins. A soft tape measure works best. For catch-and-release, use the length-only estimate to minimize handling time and stress on the fish.

tuna come in many different forms depending on the species. There are 15 species of tuna that spread across seven groups and their weight changes a lot. The smallest are the bullet tuna that weigh only 1,8 kg.

Or around 4 pounds. The atlantic bluefin tuna belong to the biggest in the tuna family and can reach maximum weight of 684 kg., what matches about 1 508 pounds. This shows huge contrast between the smallest and the biggest species.

How Big Tuna Can Be

The atlantic bluefin tuna is an enormous fish. It can reach up to 10 feet long and weigh up to 1 000 pounds. Most adults reach around 200 pounds when they hit 10 years.

On average, they measure 5 feet long and 130 pounds heavy. At 30 years old, bluefin tuna can grow to 3 metres and pass 600 kg. They grow fairly fast compared to other tuna and can live up to 20 years.

The Smithsonian Institute and the American National Marine Fisheries Service agreed, that this species can weigh up to 910 kg., so around 2 010 pounds. A huge bluefin tuna of 1 058 puonds was caught recently by Cayde Walker, what maybe marks a record for the Bahamas seas.

Four other tuna species have their own weight ranges. The blackfin tuna reach a maximum of 46 pounds and 39 inches long, although most are caught at around 19,75 inches. Skipjack tuna can weigh up to 75 pounds and grow up to 3,5 feet.

Yellowfin tuna go up to around 450 pounds in weight. The albacore stays between up to 100 pounds. Blackfin, yellowfin and bluefin are considered the heavy ones in that order.

Bluefin tuna cannot be farmed, so you can only catch them in the wild. There speed and strength makes them hard to catch, while their shortage means only a few catches of some millions of pounds yearly. Some tuna stock is fully used without space for more fishing, and some are already overfished.

tuna is also good protein with low calories. For a 100-gram serving of regular tuna there are around 144 calories, 23,33 grams of protein and 4,9 grams of fat with no carbs. A third serving of canned light tuna packed in water holds only 73 calories.

That amount is about the size of a checkbook. Tuna is naturally low in sodium. It fills you up without adding too many calories, what makes it good for weightcontrol.

Canned tuna comes in various sizes from 3 to 66,5 units depending on the brand.

When you clean tuna after a fishing trip, the edible flesh results in around 42 percent of the whole fish weight.

Tuna Weight Calculator: Estimate Fish Weight by Length

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