using the end of your index finger as a 1" measurement, I get her at 19-20", and little on the fat side, with a big head, puts her at about 6 pounds to 7 pounds, jim

SO,..Multiply the square of the girth in inches by the length in inches and divide by 800,

For example: a fish measures 38 inches in girth and 59 inches in length, so 38 x 38 = 1,444 and 59 x 1,444 = 85,196, then 85,196 divided by 800 = 106.39 or 106-1/2

so if your fish is girth: 16x16=256 and length is 20x256=5120divided by 800=6.4 pounds...I'd say thats close.