Hook size confuses a lot of newer UK anglers because the numbering system is counterintuitive – and then changes direction entirely once you move into bigger hook sizes. This guide clears up the sizing system and gives practical size recommendations by species.
[Image placeholder: A hook wallet showing a range of fishing hook sizes from small to large]
How Hook Sizing Works
Standard hook sizes run from very small numbers upward, but counterintuitively, a bigger number means a smaller hook: a size 20 hook is tiny (suited to a single maggot), while a size 6 hook is comparatively large. Once hooks get big enough, sizing switches to an “aught” system (1/0, 2/0, 3/0 and upward) where the numbering flips – a bigger number now means a bigger hook. A 2/0 hook is bigger than a 1/0, which is itself bigger than a size 1.
Hook Sizes by Species
Roach, rudd, small skimmers: size 16-20, matched to single maggot, small pinch of bread, or a single grain of corn.
Bream, tench, general coarse: size 12-16, matched to double maggot, bread flake, or a single boilie/pellet hookbait.
Chub, barbel: size 8-12, matched to larger bread flake, luncheon meat cubes, or pellet hookbaits, with barbel sometimes needing a stronger-gauge hook for their power even at moderate sizes.
Carp: size 6-10 for most method feeder and boilie fishing, occasionally down to size 4 for bigger single hookbaits or up to size 12 for smaller pellet/corn presentations on pressured waters.
Pike: size 4 to 2/0, usually as trebles for deadbaiting or single hooks for larger lures, always fished on wire trace regardless of hook size due to pike’s teeth.
Zander and perch: size 4-8 for bait fishing (zander deadbaiting, perch on worm), or appropriately sized trebles/single hooks matched to lure size for lure fishing.
Sea fishing (bass, cod, general bottom fishing): size 1 to 6/0 depending on target species and bait size, with bigger baits like whole mackerel needing hooks up toward 4/0-6/0 and smaller bait presentations for whiting or flounder sitting around size 1-4.
Barbless vs Barbed
Many UK fisheries require barbless (or micro-barbed) hooks to reduce injury and speed up unhooking – check the specific water’s rules. Barbless hooks are also simply easier and quicker to remove even where not mandated, and cause less damage on a missed strike.
Matching Hook to Bait, Not Just Species
The bait size matters as much as the target species when choosing a hook – a size 16 hook suits a single maggot regardless of whether you are after roach or a smaller bonus fish, while a size 8 suits a bigger piece of bread or meat regardless of the specific species you expect to catch. See our full fishing hooks guide for pattern types (eyed, spade-end, wide-gape, and more) alongside sizing.