Fish Weight Estimator

Estimate a fish's weight from its length and girth measurements using species-specific formulas.

Length

Girth

Species

Tab to move between fields

Estimated Weight

2.16 lbs

≈ 9 sticks of butter

Estimated Weight0.98 kg

Trophy Threshold8 lbs

% of World Record9.71%

How to Use This Calculator

Measure the fish's total length in inches from nose tip to tail tip with its mouth closed.
Measure the girth in inches at the fish's widest point, usually just ahead of the dorsal fin. Leave at 0 for a length-only estimate.
Select the species (bass, trout, walleye, pike, catfish, or salmon) for species-specific weight formulas.
Read Estimated Weight in lbs and kg — this uses both length-girth and power-curve formulas for accuracy.
Compare your fish to the Trophy Threshold to see if it qualifies as a trophy for your species.
Check % of World Record to see how your catch ranks against the all-tackle record.

How the result changes with Girth

Length: Total length of the fish from nose to tail tip in inches. Measure with the mouth closed.
Girth: Circumference of the fish at its widest point (usually just ahead of the dorsal fin). Set to 0 for length-only estimate.
Species: Different species have different body proportions. Select your species for the most accurate estimate.

Estimated Weight: Estimated weight based on length, girth, and species-specific formula.
Estimated Weight: Weight converted to kilograms.
Trophy Threshold: The generally accepted trophy weight for this species. Fish above this are exceptional catches.
% of World Record: Your fish's estimated weight as a percentage of the all-tackle world record for this species.

Identify Input Parameters
Length = 18, Girth = 12, Species = 0 = 3 input(s) provided
Calculate Estimated Weight
Estimated Weight
2.16 = 2.16
Calculate Estimated Weight
Estimated Weight
0.98 = 0.98
Calculate Trophy Threshold
Trophy Threshold
8 = 8