Estimating Fish Weight

[Fishidiot]

There's an old equation that (at least in the past) was considered pretty accurate in calculating a fish's weight based on it's length and girth. It seems to me that, in more recent years, more accuarate or species- specific equations have been derived.....nevertheless, I've long used the old one and consider it pretty accurate.
The equation is:

length X girth(squared) divided by 800

In the recent Yough report in the Stream Reports forum there's a photo of DaveS with a spectacular brown he estimates was 23 inches and about 6 pounds in weight. I downloaded the photo and made some measurements and estimates. It's a thick fish that I'd estimate, very conservatively, at 14.75 inches in girth. Using the old equation....it comes out at 6.25 pounds.

It seems Dave is a pretty honest guy. 🙂

 

[DaveS]

So there you go. Thanks Dave.

Actually, I'd recently recieved as a gift, a 5lb log of Seltzer's Lebanon Co. Balogna. (Its really good stuff). And I just figured the fish was bigger that the balogna!


But thanks for formula. I'll take a few measurements and see if it applies to lunchmeat as well!

 

[SBecker]

You have had to already eat half of it already. So how are you gonna measure it?

 

[greenghost]

Being lousy at math, I'll use the "Bologna Formula" from now on. I assume any brand would suffice. And that the girth of the fish would have no bearing on the girth of the angler after eating the bologna.

 

[pete41]

Ah yes,The full of bologny formula-
works for numbers also.
🙂

 

[albatross]

Thanks for the simple formula DaveW. We were another mile or two down river before it occurred to us we should have got a girth measurement. I did pull a scale out of my satchel, but predictably the batteries were dead...

 

[SBecker]

albatross wrote:
Satchel

Purse

 

[albatross]

SBecker wrote: "Purse"

Hey, at least its camouflage...

 

[SBecker]

Lol 🙂

 

[albatross]

 

[Aducker]

Thanks for the formula, I was looking for that.

You can figure the circumfrence a little closer by figuring out the diameter. So in you picture D= 5.2 or pie(3.14) x D (5.2) = 16.32 C.
I just didn't want you to sell yourself short on the esitmated size of the fish🙂

So your fish picture is maybe about 7.66 lbs. you gained a half pound or you could just round up as some do to 7 lbs, 8 or 9 lbs depending on who your talking to.

 

[SBecker]

albatross wrote:

Murse

 

[Aducker]

Thanks for the formula, I was looking for that.

You can figure the circumfrence a little closer by figuring out the diameter. So in you picture D= 5.2 or pie(3.14) x D (5.2) = 16.32 C.
I just didn't want you to sell yourself short on the esitmated size of the fish🙂

So your fish picture is maybe about 7.66 lbs. you gained a half pound or you could just round up as some do to 7 lbs, 8 or 9 lbs depending on who your talking to.

OK forget my stupid formula, I keep forgetting fish arn't completley round.. 😳

 

[JackM]

Aducker wrote:


OK forget my stupid formula, I keep forgetting fish arn't completley round.. 😳

Well they are very well-rounded-- and smart, damnit, they're smart I tell you!

 

[DaveS]

Regardless of the length, or Girth, or any sum there of...

Never let the facts get in the way of a good story.

 

[SBecker]

Turtles having sex in Junction pool is great story.