Weight of Fish

Dan Knox wrote to ask about the measurements of the browns that I posted. Sorry I didn’t make that clear Dan. The first measurement is the length in inches, the second is the girth in inches measured just in front of the dorsal fin. Rather than suspend these big fish by their jaws and chance damaging them, we take these measurements and then translate them into weight using the following formula: The square of the girth x length divided by 750. Some anglers divide by 800, but we have found that 750 more accurately represents the true heft of these fish. So, for example, the 36 x 21 fish would weigh: (21 x 21 x 36)/750 = 21.168 pounds; 21 is close enough. Note this, for a 36 inch fish, the girth is the weight. For the 35 x 20.5 brown, the weight would be: (20.5 x 20.5 x 35)/750 = 19.61 pounds; 19 1/2 is close enough. For the 34 x 20 inch fish, the weight would be (20 x 20 x 34)/750 = 18.13 pounds; 18 is close enough.


  1. Dan Knox says:

    Thanks, Gary,
    That is very helpful.