Smallmouth Bass Weight Conversion Chart

Smallmouth Bass Weight Conversion Chart

Several methods are available to estimate the weight of a fish. Some use length as well as girth measurements. Weight also can be estimated using only length measurements based on relationship between length and weight. Length-weight equations can be developed for specific waters, regions (e.g., states), or for a particular species.


Formulas containing length as well as girth are often most accurate for estimating weight, because the fatness or plumpness of the fish is accounted for. If only length is available, the most accurate weights often are estimated from length-weight relationships for specific waters or regions. For instance, in some waters fish might be relatively "skinny," and the weight estimate might be overinflated if based on a formula created from data on a water body where fish are "fat" or even "normal." That's why adding girth to the formula can help with accuracy. Formula's containing girth, however, also may not be as accurate as we'd like, because of inherent differences in the shape of fish and finding the right adjustment factor (or "shape" factor) to use in the formula. And it's important to measure girth carefully, and at the fish's fattest point, as girth estimates affect weight estimates powerfully.

One easy way to estimate fish weight is through the use of standard length-weight formulas. Species-specific formulas, called standard-weight equations, have been developed for dozens of fish species by fishery biologists to describe the standard growth form of a species as a whole. These relationships often are used to assess body condition (the relative weight or plumpness of a fish), which provides an index of a fish's well-being, such as whether there are forage shortages or surpluses, and can sometimes reflect fish growth rate.

These standard length-weight formulas are often developed using thousands of fish from hundreds of populations across the range of a species, so they describe the "general" growth form of that species. For instance, the equation for black crappie was developed using over 20,000 fish across a range of sizes from 175 populations across the geographic range of black crappie.


*An important thing to keep in mind is that these standard length-weight formulas describe fish in "above-average" condition. In fact, the weights in the tables represent the 75th-percentile in the samples for that particular length, and are not average weights. In other words, if you lined up 100 random bass of the same length in order of weight, and those bass were a good representation of the range of weights for that length, the weight provided in the table would be for the 75th heaviest fish. While it might have made more sense to use the median weight for these formulas, fishery biologists decided to go with the 75th percentile so that the standard weight at a given length was an above-average or "ideal" target to shoot for in terms of body condition. So, if your fish appears plump and healthy, the weights from the table should be relatively close. If your fish is skinny to average, it will weigh less, and if very plump and remarkably "fat" it will weigh more. Just make an adjustment. No formula is 100-percent accurate, but if you have only length and not girth, this should help get you in the ballpark. Your state fishery agency may have standard weight tables based on regional data posted on their website. These formulas use total length of the fish, measured from the tip of the snout to the tip of the tail fin when compressed.

Smallmouth Bass

Length To Weight Conversion Chart


Smallmouth Bass Weight Conversion Chart

 
12 in0.92 pounds
13 in1.18 pounds
14 in1.50 pounds
15 in1.87 pounds
16 in2.30 pounds
17 in2.80 pounds
18 in3.36 pounds
19 in3.99 pounds
20 in4.70 pounds
21 in5.50 pounds
22 in6.38 pounds
23 in7.35 pounds
24 in8.43 pounds
25 in9.60 pounds
26 in10.89 pounds
27 in12.28 pounds

Get Your Fish On.

Plan your next fishing and boating adventure here.

Recommended for You

Bass

Deep Cranking Confessions from the Pro's

John Neporadny Jr - December 18, 2017

Here's some important crankbait lessons from the big leagues.

Walleye

Spring is Prime Time for River Walleyes

Dan Johnson - February 22, 2018

Across the Walleye Belt, early spring is prime time to tap some of the year's best bites.

Recipes

Blackened Fish Recipe

Tommy Thompson

Blackened fish ready to serve with a side of okra and cucumber-red onion salad. This recipe is...

See More Recommendations

Popular Videos

Mustad's Inkvader Octopus Live Jig

From big fish to small, just about any saltwater game fish out there will love the new Mustad Inkvader Octopus Live Jig that Mustad's Russ Whisler shows to OSG's Lynn Burkhead.

Room Full of New Gear from L.L. Bean

L.L. Bean's Jeff Miller shares a room-full of new gear for 2020 with Game & Fish Editorial Director Adam Heggenstaller at ICAST 2019 in Orlando.

Frigid Water Smallmouths

Doug Stange swims jigs with precision for frigid-water smallmouths.

See more Popular Videos

Trending Stories

Other Fish

Best Carp Baits Today

Dan Johnson - June 29, 2018

To guide your carp quest, we've lined up the best carp baits that are easy-to-fish natural...

Bass

Largemouth Bass Length To Weight Conversion Chart

Dr. Rob Neumann - January 22, 2017

Check out this Largemouth Bass Length To Weight Conversion Chart, a simple and accurate...

Other Fish

Must-Have Striped Bass Tackle

Rick Bach - May 04, 2017

It was an August evening and I was wading the flats in Brewster, MA with my cousin. Here you...

See More Stories

More Bass

Bass

Tactics for Summer Smallmouths in Big Water

Matt Straw - June 28, 2018

Great tips for catching smallies on big water.

Bass

Tips for Bass Fishing at Night

Chris Schneider - June 01, 2018

Here's how to catch some BIG bass during the twilight hours.

Bass

Best ChatterBaits for Bass

Steve Quinn - July 30, 2018

Don't overlook this bait for big bass.

See More Bass

GET THE MAGAZINE Subscribe & Save

Temporary Price Reduction

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW THIS MONTH'S ISSUE

GET THE NEWSLETTER Join the List and Never Miss a Thing.

×