Fishing Hook Size Finder

• It starts with the speciesEach species has a baseline range of hook sizes. A bluegill starts with small hooks and a catfish with large ones.
• Technique, water and bait move the rangeWith no bait chosen, the technique shifts it; once you name the bait, the bait sets it, apart from written rules for common pairings. Salt water moves it up two steps. The bait also decides the style: an offset, wide-gap or jig hook for soft plastics, a circle hook for big live bait and cut bait, a treble for most hard baits.
• Hard baits keep their factory hooksFor crankbaits, jerkbaits, spoons and spinners the hook follows the lure. Written rules give the treble size the lure normally carries and advise replacing like for like.
• You see the sizes either sideResults also show the next size smaller and larger where the hook style offers one, and say when each is worth trying.
• Flies are sized by patternFor fly fishing the hook is the fly: the tool gives a size range for the fly type, such as a dry fly, a nymph or a streamer.

What it does not know: the gap and wire of the exact hook you are holding, or local rules on hook type such as single, barbless or circle hooks.

Read the methodology, or tell us what looks wrong.

• Hook numbering is not standardizedTwo hooks stamped 2/0 from different brands, or in different styles, can differ noticeably in gap. Compare hooks side by side.
• Circle hooks run smallA circle hook runs smaller than a J hook of the same printed size, so the tool moves a circle hook's range up one size unless a written rule gives the size. Brands differ, so compare the gap with the hook you are replacing.
• The bait usually decides the hookOn soft plastics and live bait, hook size follows the bait far more than the fish. That is why the tool asks what you are throwing.

Read the sources and limits behind this guidance.