Free tools
Fish calculators
Weight from length and age from length for 32 species. Free, no sign-up, and built on the same numbers fishline uses when it measures a fish from a photo.
Fish weight calculator
Species and length in, estimated weight out. Add a girth for a closer number on a fat or skinny fish.
Work out a weightFish age calculator
A rough age from length, read off the species’ growth curve, with a size by age table.
Work out an ageLength to weight charts by species
Every species has its own page with a full length to weight chart, typical size by age, and tips for a photo that measures well.
- Largemouth bass
- Smallmouth bass
- Spotted bass
- White bass
- Striped bass
- Walleye
- Sauger
- Yellow perch
- Northern pike
- Muskellunge
- Chain pickerel
- Black crappie
- White crappie
- Bluegill
- Redear sunfish
- Channel catfish
- Blue catfish
- Flathead catfish
- Rainbow trout
- Brown trout
- Brook trout
- Lake trout
- Chinook salmon
- Coho salmon
- Common carp
- Freshwater drum
- Redfish
- Speckled trout
- Flounder
- Snook
- Tarpon
- Mahi-mahi
Or skip the tape. Snap a photo and fishline measures it.
Species, length and weight from one photo. 5 free measurements every month.