Need a weight estimate

Hey guys this morning I caught this obese fella. He/she measured in at 33 inches, but I don't have the girth. Anyone have an idea of how much it could have weighed?


David Dalan

69°19'15.35" N 18°44'22.74" E
Rainbow of some kind (lake run, steelhead, whatever). I'd be in the 13#-15#, but from a photo, its a wild guess. Healed lamprey marks on the side?
Basic way to think about it 30 inches is 10 lbs and add one pound from there for each inch. Early in the run the fish tend to be higher and vice versa toward the end, not including kelts. That is for anadramous fish, Lake Run, I am not sure. Great fish regardless of method though.
weight=length x girth(squared)/690

That fish is pretty thick, and girth is squared, so I'd say easy 15#. If the fish were two dimensional, it would weigh in at about 12#. Given that it is not, a couple extra pounds would be fair.
I catch triploids of similar length and girth. I've caught two that weighed slightly over 18#s. One was 33inches, one 34, but even fatter. But without something other than the lure to gauge, I'd guess around sixteen.