Fish Weight Calculators

Freshwater fish weight calculators for Largemouth Bass, Muskie, Pike, Walleye, and Trout. The weight results will be extremely close to the actual weight of the fish. At the bottom of the page is a saltwater fish calculator for big game fish such as Marlin, Swordfish, Wahoo etc.
For some saltwater fish such as Grouper you will get a closer weight calculation by using a freshwater fishing calculator for the freshwater fish that most closely resembles the body dimensions of the saltwater fish you want a weight for. In this case a Grouper would resemble the body style of a Largemouth Bass even though a Grouper can grow much larger.
Large Mouth Bass

Bass Weight Calculator

Length² x Girth ÷ 1,200 (length x length x girth ÷ 1,200)
Enter the length in INCHES:
Enter the girth in INCHES:
Press to calculate the weight:
The fish weight in POUNDS:

Muskie & Pike Weight Calculator

Length³ ÷ 3,500 (length x length x length ÷ 3,500)
Enter the length in INCHES:
Press to calculate the weight:
The fish weight in POUNDS:

Walleye Weight Calculator

Length³ ÷ 2,700 (length x length x length ÷ 2,700)
Enter the length in INCHES:
Press to calculate the weight:
The fish weight in POUNDS:

Trout Weight Calculator

Length x Girth² ÷ 800 (length x girth x girth ÷ 800)
Enter the length in INCHES:
Enter the girth in INCHES:
Press to calculate the weight:
The fish weight in POUNDS:

Saltwater Big Game Fish Weight Calculator

Saltwater Big Game Fish Calculator Convert the length & girth of a marlin or similar billfish into total pounds. Know how large that release really was.
Enter the Length in INCHES:
Enter the Girth in INCHES:
Press to calculate the weight:
The fish weight in POUNDS: