A fishing hook is the one piece of tackle that touches the fish, and it is the cheapest to get right. Everything about a hook is in seven parts and two numbers: the point, barb, bend, shank, gap, throat and eye, and then a size and a wire gauge. Learn the size system once, learn what each hook shape is for, and the size-by-species chart below does the rest.
Circle hooks jaw-hook tuna and billfish nine times in ten and cut deep hooking in striped bass fourfold; in the Gulf they are the law for reef fish on natural bait.
Start here
- Fishing gear — the section hub.
- Fishing line — the knot and the line test have to match the hook’s wire.
- Catfish — the species where hook size matters most, because the bait is a chunk of shad or a live bluegill.
- Jigs and rigs — the rigs that put a worm hook or a drop-shot hook to work.
How hook sizes work
The scale has two halves. Small hooks are numbered 32 down to 1, and the hook gets bigger as the number gets smaller: a size 10 is a panfish hook, a size 1 is a bass hook. Above size 1 the scale flips to “aughts”, written 1/0, 2/0 and so on up to about 20/0, and now the hook gets bigger as the number rises: a 5/0 is a catfish hook, a 10/0 a tuna hook. The number describes the gap, the distance from point to shank, which is what decides how big a bait the hook carries and how big a mouth it fits. Sizes are not standardised between makers, so a 2/0 from one brand is not exactly a 2/0 from another; the drawn-to-scale chart on the hook-size page shows how much they vary.
The hook types and what each does
| Type | What marks it | Used for |
|---|---|---|
| Bait (J) hook | The plain shape; baitholder versions have barbs on the shank | Worms, minnows, general bait fishing |
| Circle hook | Point turned back toward the shank | Live and cut bait; sets in the corner of the mouth without a strike |
| Octopus | Short, curved shank, light wire | Leeches, minnows, walleye, drop shot |
| Aberdeen | Long shank, light wire that bends free of snags | Crappie in timber, bluegill |
| Kahle | Wide gap, between a J and a circle | Live bait for flounder, catfish |
| Siwash | Long shank, open eye | Replacing trebles on spoons and spinners where single hooks are required |
| Worm / EWG | Offset bend below the eye, wide gap | Texas-rigged soft plastics, weedless |
| Jig hook | Eye bent 60 or 90 degrees | Moulded into jig heads |
| Drop-shot hook | Small, light, straight eye | Drop shot, wacky and Neko rigs |
| Treble | Three points on one shank | Crankbaits, jerkbaits, topwater; cut bait for catfish |
Size by species
The chart below is the retail and guide consensus; the species pages refine it by bait size.
| Species | Hook | Size |
|---|---|---|
| Bluegill, sunfish | Aberdeen | 8–12 |
| Crappie, perch | Aberdeen | 6–10 |
| Trout | single bait hook | 10–14 |
| Walleye | octopus or J | 4 to 1/0 |
| Smallmouth bass | worm hook | 2/0–3/0 |
| Largemouth bass | EWG worm hook | 3/0–5/0 |
| Channel catfish | circle | 2/0–4/0 |
| Blue catfish | circle | 5/0–8/0 |
| Flathead catfish | circle, live bait | 7/0–10/0 |
| Pike | treble or single | 2/0–5/0 |
| Redfish | circle | 1/0–3/0 |
| Snapper | circle | 2/0–5/0 |
| Grouper | circle | 8/0–12/0 |
| Tuna | circle | 7/0–10/0 |
Circle hooks and the law
A circle hook is fished by not striking: Maine’s Department of Marine Resources tells anglers to “simply point the tip of the rod at the fish and slowly begin to reel in. The hook will set itself, usually in the corner of the mouth.” Cooke and Suski’s 2004 review of the studies found circle hooks reduced release mortality by about half relative to conventional hooks, with fewer gut-hooked fish, and that finding is now regulation in several places: non-stainless circle hooks are required with natural bait for Gulf of Mexico reef fish under federal rule, for striped bass with bait in Maryland, in North Carolina’s ocean waters since 2021, and in Maine since 2013. The circle-hook page keeps the table by jurisdiction. Barbless hooks are the other conservation argument: a meta-analysis of freshwater studies put mean mortality at 8.2% barbless against 14.6% barbed, mostly because unhooking takes half the time.
Where to go next
The fishing line hub explains why braid needs a leader and which knot each line takes; the reels hub covers the drag that keeps a light-wire hook from straightening. For the fish themselves, start with bass and catfish, the two species this site’s hook advice is built around.