Knowing a reliable method to calculate the weight of largemouth bass can be helpful to determine if the basses weight is accurate. The formula that I have used for over 30 years is: length X length X girth divided by 1200 = weight in pounds. Bass do not grow the same every where and this formula takes into consideration most of the factors that affect weight. length is defined by measuring the fish laying flat with it's mouth closed. The length is measured from the closed tip of the basses mouth to the center of the tail along the lateral line. The girth is measured around the widest part of the bass, usually perpendicular to the center of the front dorsal fin, around the bass behind the pectoral fins. I usually lay a wet towell on the bottom of the boat, lay the bass on the towell and use a length of fishing line and cut to length to measure the bass. The girth piece of line I tie an over hand knot in the middle to identify it latter. Weigh the bass on a scale and release it immediately if possible.
A bass that was 24 1/2 inches long with a girth of 19 1/2, 24.5 X 24.5 X 19.5 divided by 1200 = 11.7 lbs. Most LMB have a girth that is 80% of the length, Florida LMB can be 90 to 100% and spots and smallmouth tend to be 75% girth to length. Girth is the variable that depends of the health of the ecosystem and the bass. This formula is as accurate as your measurements with about 2%.
Tom
Ps; The formula can be helpful to determine if the bass may have swallowed a heavy object, when records are being claimed for example.
A bass that was 24 1/2 inches long with a girth of 19 1/2, 24.5 X 24.5 X 19.5 divided by 1200 = 11.7 lbs. Most LMB have a girth that is 80% of the length, Florida LMB can be 90 to 100% and spots and smallmouth tend to be 75% girth to length. Girth is the variable that depends of the health of the ecosystem and the bass. This formula is as accurate as your measurements with about 2%.
Tom
Ps; The formula can be helpful to determine if the bass may have swallowed a heavy object, when records are being claimed for example.