4 replies to this topic

[Borms]

I've been advised that using a 'scale' is no longer the way to determine the weight of a fish, as it causes harm to the gills.  Curious as to how many of you have used these formulas? Are the accurate?

 

On-Line tool

 

http://www.ontarioan...info/weight.cfm

 

 

Manual Equation

 

Walleye: Length x Length x Length divided by 2,700 For example: An 18-inch walleye weighs approximately 2.16 pounds [5,832 (18 x 18 x 18) divided by 2,700=2.16].

 

Pike: Length x Length x Length divided by 3,500

 

Sunfish: Length x Length x Length divided by 1,200

 

Bass: Length x Length x Girth (girth is the distance around the body) divided by 1,200

 

Trout: Length x Girth x Girth divided by 800

[troutddicted]

Used the formulas for brook trout a few years back however we will never know the real weight of the fish.  The calculator gave us a number which we felt was quite appropriate for those fish however we will never know for sure.

 

My guess is that these calculators on average are good enough but won't apply well to all fish.  Take pike for example... cubing length then dividing by 3,500?  Doesn't even take girth into consideration.

[FrequentFlyer]

Used the formulas for brook trout a few years back however we will never know the real weight of the fish.  The calculator gave us a number which we felt was quite appropriate for those fish however we will never know for sure.

 

My guess is that these calculators on average are good enough but won't apply well to all fish.  Take pike for example... cubing length then dividing by 3,500?  Doesn't even take girth into consideration.

 

 

exactly, a 46 inch pike with a 20inch girth is not going to weigh the same as a 46 inch pike with a 12 inch girth

 

also from http://www.garden-is...-calculator.htm

 

Northern Pike Weight

The formula to calculate the weight for a Northern Pike that is 40 inches long and has a girth of 20 inches is as follows. Northern Pike have a shape factor of 1000 and a girth ratio of (.52)

WEIGHT = LENGTH x GIRTH² / SHAPE FACTOR

• WEIGHT= 40 x (20²) / 1000
• WEIGHT= 40 x 400 / 1000
• WEIGHT= 16000 / 1000
• WEIGHT = 16.0 pounds

[Swing4Steel]

For trout I've used lxgxg ÷800. As I get older I care less and less about weight. Length really only matters as that 12 lb hen in the fall/winter is like 9 in the spring

[FrequentFlyer]

For trout I've used lxgxg ÷800. As I get older I care less and less about weight. Length really only matters as that 12 lb hen in the fall/winter is like 9 in the spring

 

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