How accurate are weight calculators? Hmmm...

[Keithscatch]

Friend of mine sent me this info about a SAL (ShareLunker) fish caught at Lake Fork. I know these numbers to be exact as they are weighed and measured by biologists at TP&W. Here they are:

ShareLunker No. 424

Caught by Eddie Horn of Alba, TX

November 25, 2006 in Lake Fork

13.79 pounds, length 26 inches, girth 20.5 inches

Bait/Lure: 6" Black Zoom Lizard

Water Body Record? No

Day of Week: Sat

Moon Phase: FQ-3

Going to the BR weight calculator and punching in those numbers gives us a weight estimate of only 11.548333333333334lbs. Pretty good descrepency.

Has anyone else seen these calculators to be close or accurate?

[KU_Bassmaster.]

I have applied the weight calculator to SAL's in the past and it seems the weight calculator under shoots them just about everytime.

[Raul]

Length 23 "

Girth 22"

BR weight calculator: 9.69833 lbs

Actual weight at certified scale: 9.86 lbs

Difference: 0.16 pounds

BR 's weight calculator is quite accurate in my opinion.

[BucketmouthAngler13]

I think the problem with the BassResource.com calculater is that the option for Bass also includes Crappie and Panfish. This probaly messes with the weight of large bass.

[KU_Bassmaster.]

http://www.tpwd.state.tx.us/spdest/visitorcenters/tffc/budsharelunker/archives/index.phtml?seas=20&Submit=Go

I just did about the first 5 or 6 on the list. All of them under shot and most by pretty large margins 1 lbs to 3+ lbs.

I know that the calculator is just an estimate, but I am not so sure it is even that great at that.  Best thing to do is buy a scale.  It's a CHEAP price to pay for peace of mind.

[flechero]

I think the problem is girth.  On SAL sized fish they are so thick all the way through the length of the body that it's abnormal.  If you look only at lengths, fish that sized are far more common than the SAL's are.  So they aren't "normal" in thickness.  "normal" big bass have a gut but these big girls are thick from head to tail.  

[Captain Cali]

Interesting. I wonder myself.

The 10.5 I caught this past summer was 26.75" x 20". The calculator reads 11.9260lbs.

That is 1.4 pounds difference. However, it was the first and only fish I have ever measured so there was probably something we did wrong.

25.5" x 20" was probably more like it. Calculator reads 10.8375. Only 0.33 pound difference.

Hmmmm....25.75" x 20" = 11.0510 pounds. Now I'm really interested!! Could I really have met her twice in two weeks??

[fourbizz]

I don't think that they are accurate at all, you also have to take into account density of fish. My big one was 1 inch longer and 1 inch bigger in circumference than the SAL that Keith showed us. She was measured be an accomplished trophy hunter and weighed on a high end Salter digital. She weighed .69 pounds less than that SAL even though she was dimensionally bigger. Crazy

[George Welcome]

Weight caculators are based on torpedo shaped bass which includes most of North America's bass population. However, both Texas and Cal. will differ as many of their fish have larger girths than normal.

Total Length in Inches            :      Length in Millimeters:                  Weight in Pounds:

26                  660.4                  11.96750158

                                   

Maximum Girth in Inches:                  Girth in Millimeters:                  Weight in Kilograms:

20.5                  520.7                  5.439773444

                                   

     Optional weight estimate based on TL*TL*G/1200:                              11.5

           (Rough estimate for torpedo shaped fish like bass)                        

     Optional weight estimate based on TL*TL*G/1000:                              13.9

           (Rough "California" estimate for full-bodied fish like gravid bass)                        

     Optional weight estimated based on TL*G*G/800:                              13.7

           (Rough estimate for bass, per Outdoor Life and Hal Schramm)                        

[SPEEDBEAD.]

You gotta figure...most of the Cali/Texas/Florida bass are a totally, or as 4bizzle would say toadali, different type of bass than what is found in the rest of the country. Common sense would tell you that these calculators would be based on a "normal" or "common" bass as opposed to the super-giant dimensions of the pigs caught in the special area.

I think George Welcome has it right, as usual....

Wayne

[.ghoti.]

If you don't have a decent scale, you won't know what you caught.

In that case use whichever formula makes you feel the best.

It's just a guesstimate.

Not accurate.

Too many variables.

[senile1]

If you don't have a decent scale, you won't know what you caught.

In that case use whichever formula makes you feel the best.

It's just a guesstimate.

Not accurate.

Too many variables.

Well put, ghoti.  I can't imagine not having an accurate scale when you know the fish you have in your hands could be a personal best.  

[Bassinfreak2]

Speaking of decent scales. What would be a good one to buy and how accurate would it be? Those X tools scales cost a pretty penny but I would be willing to pay for higher accuracy.

[KU_Bassmaster.]

Speaking of decent scales. What would be a good one to buy and how accurate would it be? Those X tools scales cost a pretty penny but I would be willing to pay for higher accuracy.

check em' out on Ebay. I got my significantly less that what they are in the stores. Cool features and accurate. I test mine about once a month with a 5 and 10 lbs weight I have in the garage. Dead on everytime so far in the year I have had it.

[Zel]

I agree with the comments where they state that it depends on what part of the country you are in.  In Pennsylvania I have used the estimator provided by the Pennsylvania Fish and Boat Commission (and have broke it down even further to 1/4 range, using math).  We used it in our club paper tournaments and they were pretty accurate until you get over 20 inches, then it was a crap shoot. I was a tournament director, and  often used a Berkley digital scale to compare to the paper weights, and it was pretty good.  Also, during the spawn, when the females are loaded with eggs, it will not be as accurate.

Here is a link to the Pennsylvania site:

http://sites.state.pa.us/PA_Exec/Fish_Boat/images/pages/fishin1/weightlength3.pdf

[Guest avid]

If a guy doesn't carry an accurate scale, he can guess or use a fish calculator.  

For most fish, the calculators seem to be pretty accurate.  If he catches something in the double digit category you can bet he's getting weighed.  If not,  I wouldn't be very impressed with his "calculation" one way or the other.

[Bassinfreak2]

Thanks KU_BASSMASTER. I will check out ebay. From reading this thread it sounds like the fish calculators are a little to far off for my comfort.

[ring fry]

I've had two of the Berkley $20.00 scales.  The first one was about 10 to 15% off.  The one I have now is right on at 2.5#, 5#, and 10#.  I've thought about the higher dollar scales, but I can't justify it.

[Keithscatch]

Great comments everyone.

Thanks.

[Papa_Tom]

I always reference fish I catch by length....a 20" er.  I have weighed several fish over the years.  I have used a number of different hand held scales as well. Spring and digital.  I used to take them (scales) to work and weigh one pound blocks at the start of each season (installing new batts).  Progressively weigh blocks in a bag up to seven or eight and check the deviation.  Sometimes it was pretty close, but it wasn't always in the real world.  I've compared mine to guys who have "checked" theirs and the differences under inspection can be pretty great.  I would buy a good scale, if I were confident that it really was accurate.  Maybe the X tool.

[sirmo]

Here's another one for ya.

Friend of mine caught this guy...

Stats were...

11lbs 14oz (weighed on 2 sets of digitals)

29.25" length

19.5" Girth

BR Calculator says....16.36lbs !!!!

Every bass is different....there is no formula.