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Anyone have opinions about the accuracy of fish weight calculators that you find online?
I caught my personal best flathead catfish a week ago, and according to the couple of length to weight converters I tried, it weighs between 4 and 6 pounds. It sure seemed heavier than that when I was trying to hold it up for a picture, although I'm sure that's what everyone always says...:eek:.
This fish was a wee bit over 24" and pretty much exactly 14" around.

On a related note: Is there such a thing as a decent quality, reasonably priced, reasonably accurate, portable scale? I've been targeting flatheads in the French Broad and I'm hoping I'll need a scale accurate to over 50 pounds eventually, but as far as I know (which isn't much) no F.B. catfish anglers have quite hit that mark. Yet;).

Amphibian Salamander Terrestrial animal Tail Fish
Yellow Fish Fin Tail Food
 

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berkly makes a digital portable scale but it only goes to 50 pounds keep them dry and there fine and acurate 20+ at wally world
 

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If there's enough data available, there's often a species-specific formula for calculating weight from length/girth, and vice versa. Since you're targeting flatheads specifically, you might want to do some digging either online (google scholar) or at your local college/university library, and see if maybe someone has compiled the data and has an accurate formula.

I usually have better luck using the scientific name (Pylodictis olivaris) in searches for this kind of thing. You'll also want to watch out for the difference between "standard length" and "total length". Standard length doesn't include the tail, while total length does. http://en.wikipedia.org/wiki/Fish_measurement.
 

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OK, so I did a quick search and found the following formula for flatheads published in 2000:
http://www.informaworld.com/smpp/content~db=all~content=a932037131

y = 3.230(x) - 3.661 (where y = log10 of weight and x = log10 of length).

If the total length was just over 24", I'll use 22" for standard length, which gets you a weight of approximately 4.7 lbs. I've never caught a flathead, but that seems about right based on my experience with fish of that size that are similarly shaped (ie bass, bowfin).

This formula doesn't include girth, so if 14" is significantly above or below average, your fish may have weighed a bit more or less, but I think this is probably pretty close - to me, it looks like a normal healthy fish, not too fat or skinny.

Like h2ohh, I've also mostly given up on weighing my fish. I'm happy to get a length measurement and a couple good photos. If it's a really big fish, I'll also try to get a girth measurement so I can at least ballpark the weight, but for me it's not worth punching a big hole in the fishes jaw (other than the one I already put there with the hook) just to get a weight, unless it's a potential record.
 

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Most calculator's go by "Length X Width X Width / 800= X
So 24X14x14/800= 5.88 lbs.

The only accurate way to tell is by a scale because there are so many variables on fish types, long, thick, fat bellied, skinny, panfish (bream/crappie) versus bass type fish and so on.
 

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fish in comparison to the fingers in the photo Id say 5 - 5.5lbs. The have boney heads and weigh a touch more than you'd expect usually.. I second the berkley digital scale from walmart for price vs quality.. I had to replace my battery pretty quickly but after that its been 3 yrs or more and still fine..
 

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I also have the Berkley scale and had to change the batteris...a couple of times. Now when I finish using it I take the batters and turn them around so the scale cannot come on when something hits it......:)

Still a good investment for about $25 if you want to keep up with fish weights and not formulas to figure out weights...
 
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