How do you calculate trout weight?

Standard trout formula: (length × girth²) ÷ 800. If girth is missing, a length-only formula is used. Estimates are approximate.

What is the trout world record?

The rainbow trout world record is 48 lb, caught at Bell Island Hot Springs, Alaska in 1970.

Trout Weight Calculator

Estimate trout weight from length and girth for rainbow, brown, brook, and related stocked trout.

Quick answer: Standard trout formula: (length × girth²) ÷ 800. Compare your estimate to the 48 lb world record (Bell Island Hot Springs, Alaska, 1970).

Length (inches)Girth (inches, optional)

Estimated weight

3.24 lbs

Standard trout formula: (length × girth²) ÷ 800

Share of world record

6.8%

of the 48 lb rainbow trout world record

World record reference

48 lb · 1970

Bell Island Hot Springs, Alaska

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