Length & Girth measurement?

[First Bite]

Could someone tell me the formula to figure out the weight of a fish. Thanks guys.
Mark

[Phish_on]

Use a scale, then add 5 pounds ?

[Mike H]

For fish like salmonids:

(length * girth^2) / 750 = ______lbs

That's girth squared for the math disabled.

Mike H

[Phish_on]

Do you mean (length * girth)^2 / 750 = ______lbs
?

I'm having some trouble here ...
define "girth" ... is that top to bottom, or side to side ?

LOL Phish. You were talking about fish weren't ya?

[Phish_on]

YEAH buddy I got your salmonid right here ...

The TROUBLE I meant was ... I'm thinking of a finclipped coho here ... 24" nose to tail ... about 7" top to bottom - - - go figure:

(24*7)^2 = 28224
28224/750 = 37.632 lbs (no way)

24*7^2 = 24*49 = 1176
1176/750 = 1.568 lbs (no way)

I guess I fall under the "math disabled"
category. Just trying to understand ! LOL all you want - I will too ! Like, whatever!

[Hammer Bob]

Girth would be how big around the fish is...usually in front of the dorsal fin.

(24*18^2)/750=10.4 lbs

est. fish 18 inches in girth

[DanS]

phish,

You have to measure all the way around the fish, right in front of the dorsal fin. I'm guessing a fish 7 inches deep might be about 18 inches in girth. So plugging in the numers would give you:

24(18x18)=7776 7776/750 = 10.36pounds

Length measurement from tip of snout to center of tail. Keep in mind that this formula applies most accurately on silvers or kings. Use length x girth x girth/775 for steelhead.

Remeber when using this method to estimate the size on native steelhead not to thrash the fish around too much when taking your measurements. I've seen guys flip a fish around on the beach, as if they were trying to bread it before baking, and then let it go caked with sand. The flexible tapes used in sewing make for quick measurements and minimum damage to the fish.

Fish on......

[This message has been edited by DanS (edited 09-26-2000).]

[garyk]

Good point about careful handling of fish to be released.

In fact they now recommend that the fish's gills not leave the water. And of course try not to wipe off the slime, minimize the handling.

[smilesforu]

Here is a fish calculator I have on my site. I use it for steelhead
http://www.steelheader.net/Toppages/...calculator.htm

Tight Lines

------------------
Marty M
Steelheader.net

[Phish_on]

OK, got it !

I would NEVER be caught measuring a fish I was going to release. Taking a picture, yes ...
I'll stick to guessing. Once you've weighed a few fish, you can guess close enough. And they always get bigger when they swim away. They get A LOT bigger when they break off !