Catfish Weight Calculator: Estimate Weight by Length & Girth

🐟 Catfish Weight Calculator

Estimate catfish weight from length & girth measurements — channel, blue & flathead catfish

Quick Presets
📝 Fish Measurements
📊 Estimated Weight Results
📊 Catfish Species Quick Stats
58 lb
Channel Record
143 lb
Blue Cat Record
123 lb
Flathead Record
800
Standard Divisor
0.58
Avg Girth Ratio
15+ lb
Trophy Channel
50+ lb
Trophy Blue Cat
40+ lb
Trophy Flathead
📏 Channel Catfish Weight Reference
Length (in) Length (cm) Est. Weight (lb) Est. Weight (kg) Est. Girth (in)
1230.50.80.367
1538.11.70.779
1845.73.01.3611
2050.84.52.0412
2461.07.53.4014
2666.010.04.5415
3076.215.06.8017
3691.426.011.7920
🌊 Blue Catfish Weight Reference
Length (in) Length (cm) Est. Weight (lb) Est. Weight (kg) Est. Girth (in)
2050.85.52.4913
2666.011.04.9916
3076.217.07.7118
3691.429.013.1522
42106.746.020.8726
48121.968.030.8429
52132.188.039.9232
💥 Flathead Catfish Weight Reference
Length (in) Length (cm) Est. Weight (lb) Est. Weight (kg) Approx. Girth (in)
2050.84.01.8112
2563.58.53.8615
3076.214.06.3517
3691.425.011.3422
42106.740.018.1426
50127.068.030.8431
55139.790.040.8234
📋 Catfish Species Comparison
Species Max Record Trophy Size Avg Girth Ratio Formula Divisor
Channel Catfish58 lb / 26.3 kg15+ lb / 6.8 kg0.55–0.60800
Blue Catfish143 lb / 64.9 kg50+ lb / 22.7 kg0.58–0.63800
Flathead Catfish123 lb / 55.8 kg40+ lb / 18.1 kg0.58–0.65800
White Catfish22 lb / 10.0 kg5+ lb / 2.3 kg0.52–0.57800
Bullhead (Black)8 lb / 3.6 kg2+ lb / 0.9 kg0.50–0.55800
Wels Catfish297 lb / 134.7 kg100+ lb / 45.4 kg0.60–0.70750
📏 Measuring Tip: Always measure girth at the widest point of the fish's body, typically just ahead of the dorsal fin. A cloth tape measure gives the most accurate reading. Total length is measured from tip of mouth to tip of tail fin (not fork length).
🧮 Formula Accuracy: The standard formula (Girth² x Length / 800) is accurate within 10–15% for most catfish. Fish in heavy feeding condition (pre-spawn) may weigh up to 15% more than calculated. Post-spawn or lean fish can weigh 10% less. Use actual scale weight for official records.

Catfish can reach some truly wonderful sizes. Although fish more than 2 metres long happen rarely one knows that they can pass 2.5 metres and reach more than 100 kilos, what matches around 220 pounds. Even so different species have a lot of various typical weights.

For instance, the channel Catfish is much more small on average. Adult channel Catfish normally weighs between 2 and 4 pounds and reaches at least 12 inches. In 1964 one caught in South Carolina a 58-pound channel Catfish, that stays the world record.

How Big Catfish Can Get

Blue Catfish, on the other hand, can become much more big. It reaches up to 65 inches in length and 143 pounds in Weight, lives up to 20 years and is the biggest Catfish of North America. Some fishermen even said, that they caught blue Catfish weighing more than 100 puonds.

One fisherman photographed and estimated one sample, that seemed to weigh between 150 and 160 kilos, so around 330 to 352 pounds. In north Thailand fishermen once caught a 646-pound Mekong Catfish. Like this this species can reach truly enormous sizes.

To estimate the Weight of blue or flathead Catfish according too measures, one uses special tables. A common formula for Catfish is: multiply the girth of the fish by itself, then multiply that by the length and divide the result by 800. For instance, for a 49-inch fish with 32-inch girth one receives around 62.72 pounds.

When one uses 700 instead of 800 as divider, the results a bit range according to the source. For bass and Catfish there exists a formula, that takes the length in inches, cubes it and divides by 1600.

According to one chart, a 32-inch Catfish would weigh around 20.5 pounds. Blue Catfish of 36 inches average have 23.2 pounds according to a Weight table. Fish between 30.5 and 32 inches weighed 14 to 16 pounds, although slim samples can fall to 12 pounds.

To get precise weights, use a checked digital scale, it is a reliable tool. Some fishermen weigh the fish in a net and then subtract for the final Weight. Document every catch with length, girth and Weight, to form a general idea about the weights in a certain region.

Five-pound Catfish caught with a fly rod are not rare, and the biggest on fly reached around 8 pounds. Fish more than 15 inches long can give a strong fight. In the little finish, Catfish caught withbait on a rod average around 2.5 pounds.

Catfish Weight Calculator: Estimate Weight by Length & Girth

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