Fish Weight Calculator
Estimate weight from length and girth (by species or precise)
Measurement
Estimated weight
0 kg
※ Adding girth captures body condition and is most accurate (weight=length×girth²÷28902). Length-only uses an average species coefficient and varies by season, sex and individual.
Result
| Estimated weight | 0.67 kg (670 g) |
| Estimated range | 0.57 ~ 0.77 kg |
| In pounds | 1.48 lb |
⚠️ This calculator is a reference tool based on published fish length-weight relationships (W=a×L^b) and girth-based estimation formulas. Fish of the same length can differ greatly in weight depending on condition, season (before or after spawning) and habitat, so use a scale for an exact weight. calcstool.com assumes no liability for these results.
FAQ
How is fish weight estimated?
Two ways: (1) length+girth: weight(kg)=length×girth²÷28902, accurate regardless of species; (2) length+species: weight(g)=a×length^b using an average coefficient. Adding girth is most accurate.
Why measure girth?
At the same length, a plump vs lean fish weighs very differently. Girth reflects body volume directly, so it is far more accurate than length alone.
Is the estimate exact?
It is a reference estimate shown as a range, varying with season, sex and individual. Weigh on a scale for exact values. Enter actual weight to see body condition vs the estimate.