Calculate the weight of a largemouth bass without a scale

The world’s largest confirmed largemouth bass is 22.25 pounds. It was caught by George Perry in Montgomery Lake near Valdosta, Georgia in 1932.

For comparison, many largemouth bass weigh around 15-16 pounds at the high end.

To most fishermen, a lunker is any largemouth that weighs about 5 or 6 pounds in the northern United States. In Florida, a largemouth needs to be about 10 pounds or more to attract any attention.

You can get an average estimate of the weight of your fish in pounds using the following formula. All you need is a measuring tape to measure the length and girth.

Diagram of where to measure a largemouth bass for length and girth

Find the weight of a largemouth bass without a scale using this formula

L x G x G

  • L = Length [in inches] from nose to the fork in the tail
  • G = Girth [in inches] around the fleshiest portion of the body
  • Result = Weight of fish in pounds
  • The 800 is per Outdoor Life and Hal Schramm to calculate average bass weight.

In general, this formula will give you a close enough estimate to the weight. It won’t be good enough for official record keeping, but good enough for a fisherman’s estimate. And you’ll have a story to tell your buddies and local fishing clubs.

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