Fishing Hook Sizes Explained
By Alex Clayton · Updated 23 October 2026
A size 20 hook is barely bigger than a maggot, yet a 2/0 is a hefty piece of wire. Same kind of number, opposite ends of the scale.
That is how fishing hook sizes work. Plain numbers (20, 18, 16 and on down to 1) get smaller as the number rises. Aught sizes (1/0, 2/0 and upwards) get bigger as the number rises. There is no international standard, so a size only means the same thing within one maker’s range.
One working rule runs through everything below: pick your hook bait first, then adjust for the fish and the conditions.
The beginner trap comes first, then the chart. For the rest of your end tackle, browse our tackle explainers.
Why ‘Go Up a Size’ Confuses Beginners
Someone on the next peg says go up a size, so you swap your 16 for an 18 and end up fishing a smaller hook.
The problem is the language, not you. In angling talk, “up” and “down” describe the hook, not the number printed on the packet. Up a size from a 16 is a 14. Down a size is an 18.
On the aught side, the number and the hook move together, so up from a 1/0 is a 2/0. Size 1 sits in the middle and acts as the hinge between the two halves of the scale.
Most packets you’ll see in UK coarse tackle shops step in even numbers (20, 18, 16, 14), so a “size” usually means a jump of two.
Plain numbers: smaller number, bigger hook. Numbers with /0: bigger number, bigger hook.
Learn that line and the most common mix-up in hook sizes for beginners goes away. If you’re still unsure, hold the two packets side by side and compare the gap between point and shank.
How the Hook Size Scale Works: Size 32 to 20/0
The full scale runs from size 32, the smallest, to 20/0, the largest. Most UK freshwater anglers use only a narrow slice of it.
The number is a relative measure, not a measurement. It is generally tied to the gape, the gap between the point and the shank. If the parts of a hook are new to you, see the parts of a fishing hook first.
| Size band | Example sizes | Relative size | Typical UK use |
|---|---|---|---|
| Very small | 24 to 20 | Tiny | Single small maggots, pinkies and squatts; canal and match fishing for small fish |
| Small | 18 to 16 | Small | Maggot, caster and small pieces of bread for roach, rudd and skimmers |
| Medium | 14 to 10 | Medium | Double maggot, worm, corn and small pellets for bream, tench and chub |
| Large | 8 to 4 | Large | Bigger baits, carp and barbel baits, worm for perch |
| Hinge | 2 to 1 | Larger | Big baits, some predator and sea fishing |
| Aught | 1/0 upwards | Largest | Sea fishing and some predator rigs |
Exact dimensions vary by maker and pattern, so use the maker’s chart or the packet for precise sizes. Sizes below 24 exist but are specialist.
Read this hook size chart as a map, not a ruler. Sizes 20 down to 1 are the coarse angler’s working range; the aught half belongs mostly to sea and predator fishing.
Why a Size 10 From One Maker Isn’t a Size 10 From Another
If a size 10 is a size 10, why does the new packet look a size out?
Because there is no internationally recognised hook standard. Sizes are inconsistent between manufacturers and only consistent within one maker’s own range. Two size 10s from different brands can look noticeably different, and neither is wrong.
Pattern changes things even inside one brand. A long shank, wide gape or curved shank hook in the same size can look bigger or smaller and hold a bait differently. Wire thickness matters too: a heavy-wire hook feels bulkier than a fine-wire hook with the same number. Our guide to hook patterns and wire gauge covers those differences in full.
When you find a size that works with a bait, note the maker and the pattern, not just the number. When you switch brands, check the maker’s chart or compare the hooks side by side before you tie up a batch of rigs.
Treat the number as a guide within one packet range, not a universal measurement.
What Size Hook for Which Bait: A Hook-to-Bait Table
Know your hook bait and the table below gives you a starting size in seconds.
Match the hook to the bait so the point and bend stay exposed. A hook buried in bait misses bites because the point can’t find a hold, and a hook far too big for a single maggot looks wrong and can burst it. Our bait guides go deeper on each bait.
Hair-rigged baits are the exception. The bait sits on a short length of line off the hook, so you size the hook to the bait’s bulk and the fish.
| Hook bait | Typical starting size | Notes |
|---|---|---|
| Single maggot, pinkie or squatt | 18 to 22 | Fine wire for small fish |
| Double maggot or caster | 16 to 18 | |
| Punched or flake bread | 14 to 18 for punch, larger for big flake | Size follows the piece |
| Sweetcorn (1 to 2 grains) | 12 to 16 | |
| Worm | 10 to 14 for small worms, larger for a whole lobworm | |
| Small hooked pellet | 12 to 16 | |
| Luncheon meat cube | 8 to 12 | Size follows the cube |
| Hair-rigged boilie or large pellet | 4 to 10 | Hook sits off the bait on a hair |
| Deadbait for pike | Trebles or large singles, often around 4 to 2/0 | Used with a wire trace |
These are starting points. Go up or down from here as the next sections explain, and check the packet, because sizes vary by maker.
So what size hook for sweetcorn? Start on a 14, the middle of its range, and adjust. Ignore the table only when a fishery or match rule sets your hook for you.
Hook Sizes by Species: Typical UK Starting Points
A species-only chart can hand you a size that fights your bait. Use these bands to check the choice from the hook-to-bait table above, not to replace it.
| Species | Typical range | What changes it |
|---|---|---|
| Roach and rudd | 16 to 20 | Smaller in clear or cold water |
| Bream and tench | 12 to 16 | Bait size and fish size |
| Chub and barbel | 8 to 12 | Stronger wire on rivers with flow and snags |
| Perch | Around 4 to 8 | Larger for whole worms and bigger baits |
| Pike | Trebles or singles around 4 to 2/0 | Deadbait size; always on a wire trace |
| Sea fish | From about 1 into the aught sizes | Depends heavily on species and bait |
On Windermere I let the bait decide the hook for bream on the feeder, and my pike rigs are built around the deadbait and the wire trace rather than a number on a packet.
Carp hook sizes
Carp hook sizes typically fall between 6 and 10, almost always on a hair rig. The size follows the hook bait, the strength of the fish and any snags, and a bulkier bait usually calls for a bigger hook. Wire strength matters as much as size, so choose a pattern built for hard-fighting fish. Pop-up and bottom-bait set-ups are covered in our rig guides.
If you’re between two sizes for a species, take the one that suits your bait.
When to Go Up or Down a Size
One size change is often the cheapest adjustment you can make on the bank.
Go down a size when:
- the water is clear or cold and fish are cautious
- your baits are small
- bites are tentative
Go up a size when:
- your baits are bigger
- the fish are larger or stronger
- snags or flow call for a stronger hook
- small fish are a nuisance and you want to pick out bigger ones
Keep the rig balanced: a small fine-wire hook on a light hooklength, a strong hook on heavier line. Light float rigs and small hooks go together, so see our guide to matching your float and shotting.
The GOV.UK tackle rules for England and Wales list no national hook size or barbless rule, but local byelaws and fishery rules can set one. Check the fishery or club rules and the local byelaws before you fish. Barbless hooks make unhooking easier and are kinder for catch and release, but they can slip out if the line goes slack. Our barbless hooks guide has the detail.
A smaller hook usually brings more bites but needs more care playing fish. A bigger hook holds better but draws fewer bites from shy fish.
A Starter Hook Box: Three Size Bands to Carry
Three packets, chosen by band, cover most first sessions on UK freshwater.
- Small, 16 to 20: maggot, caster and bread for roach, rudd and other silver fish.
- Medium, 8 to 12 (stretching to 14): corn, worm and pellet for bream, tench and chub.
- Larger, 4 to 6: bigger baits and bigger fish.
Predator and sea anglers need their own hooks and traces, which sit outside this box.
Buy one pattern you trust in each band, ideally from the same maker, so the sizes stay consistent with each other, for the reasons covered in the maker-to-maker section above. Our guide to building a terminal tackle box covers the rest.
Start with the band that matches the bait you use most, and add the others as you need them.
Frequently asked questions
Is a bigger number a bigger fishing hook?
No for plain sizes, yes for aught sizes. A size 20 is smaller than a size 10, because plain numbers shrink as they rise. On the aught side, a 3/0 is bigger than a 1/0. Size 1 is the changeover point. The hook size chart on this page shows the full scale.
Are hook sizes the same across brands?
No. There is no international hook standard, so sizes are only consistent within one maker's range, and pattern and wire thickness change how a hook looks. Compare hooks from the same maker and pattern, and check the maker's chart when you switch brands.
What size hook should a beginner use?
Start from your bait. A size 16 to 18 suits maggot or caster, and a 12 to 14 suits corn or worm, as typical starting points. Then go up or down one size depending on the fish and conditions. The hook-to-bait table on this page gives sizes for other common baits.
Are there rules on hook size in England?
The GOV.UK tackle rules page lists no national hook size or barbless rule, but local byelaws and fishery rules can, so check before you fish. GOV.UK also says you must not keep a fish that is foul hooked, meaning hooked anywhere other than the mouth or throat.