Fish weight formulas!

[slipbob]

I came across some formulas for approximating the weight of fish that seem pretty good. 

Pike would be Length x length x length divided by 3500

Walleye would be Length x length x length divided by 2700

Bass would be Length x length x length divided by 1600

Bluegill would be Length x length x length divided by 1200

Another general forumla would be girth x girth x length divided by 800

 

[devil-man]

That's pretty good, Slipbob, at least for bass.
My biggest one so far this year was 21". It weighed 5-10.
The formula gives you 5.79 #.

[Scott]

I can't spell or do math so I use this. 

http://www.iceshanty.com/iceshanty/fish_weight_calculator.php

[rgfixit]

MY formula is a lot simpler and works well for me...

1 fish (any species) in the frying pan, weighs more in my stomach than all the others I let go
RG

[big walleye]

rgfixit

[TroutFishingBear]

These are weights in ideal conditions of course; they are not exact but they get you in the ballpark. There are other factors that this does not take into account: The content of the fish's stomach for example. A pike may have eaten a 1 lb. baitfish but then be estimated at 5 lbs but really be 6 lbs.

But what I do like about these are not the fact the weight the give you (scales do that much better), but help fisherman realize it is usually the girth that helps fish weigh alot, not necessairly length.

[deerhunter]

i got one of those little digital scales. cheap and very acurete.

[TroutFishingBear]

i got one of those little digital scales. cheap and very acurete.

Yes, they are much more accurate than the other ones. How much did yours cost?

[TroutFishingBear]

I used the aforementioned ice shanty calculator on the measurements of a few of my big bluegill and was surprised by the accuracy. One actually weighed 2 lbs 9 oz (well, a teeny bit over 8 oz) and the calculator gave me 2 lbs. 6 oz roughly. Nice!!!

[Thriller]

Coming out of the photos section, estimating the size of a 24.5 inch, girth 18 inch largemouth bass.

http://www.outdoorsite.com/fishingcalc/index.cfm (would make it 9)
http://www.fishdreams.com/calculator.all_species.html (gives 9.9...same as previous post)
http://www.gsmfc.org/sasweb/fishsize.htm (this one is for saltwater fish only, but thought I'd include it...)
http://www.liveleaderboard.com/fish-weight.asp (walleye, pike, bass and bluegill - 9.19 lb)
http://www.iceshanty.com/iceshanty/fish_weight_calculator.php (IceShanty)
http://www.bcfishingreports.com/fish_calculator.html (for steelhead & salmon)
http://www.rodnreel.com/fishcharts/FishCharts.asp (for species around the Gulf Coast - no pike, walleye, etc.)
http://www.bassresource.com/bassfishing/fishcalculator.html (this one has 6 fish types, so may be a bit finer than some of the others - just over 9)

You get the picture...there are many others.  Many of them divide into only 2 types, so I think would be a bit more of a rough calculation.  The ones for walleyes tend to be on the light side for the big fish (either that or everyone who catches 28-30 inch fish are grossly overestimating the weight).