Think of being wrestled to the ground, grabbed by the lip and dangled over a cliff for a time and then being put back on your two feet, released with soft tones of “there you go, big guy, have a nice day”. NICE DAY MY *****!!!

As fisherman we are not going to be able to eradicate the trauma we cause our aquatic adversaries, but we can do things to ease it. One such approach is in the weighing of our catch. Let’s use some of that math many us questioned the use of while struggling with solid geometry in School.

You can approximate your fish as an oblate ellipsoid, using its length width and height. An oblate ellipsoid is an ellipsoid where none of the three axes are of equal length. The equation for the volume of such a geometric solid is pi times length times height times width divided by 6 …..STOP!!!!! …….Fishing is supposed to be relaxing!!

Here it is in simple terms. The general formula for all fish is:

WEIGHT = (length x girth2) / 800

Where:

length & girth are measured in inches,
Girth is the distance around the body of the fish at its largest point, and all answers are in pounds.
To measure your fish:

A = length and B = girth

This formulas is the generally accepted formula for all fish with a 5% error factor. Below you will see some formulas specific to species. Using these will reduce the error factor for these species. As a general rule, even for marlin and the like, the “trout weight” formula will do just fine.

Forumulas
bass weight = (length x length x girth) / 1,200

pike weight = (length x length x length) / 3,500

trout weight = (length x girth x girth) / 800

For example, you catch a 16 inch trout with an 11 inch girth. Using the formula for trout above: (16 x11 x 11) / 800 = 2.42 pounds. Your trout weighs approximately 2.42 pounds.