Fishing hook sizes can be rather confusing when you first start fishing. It’s not always obvious what fishing hook sizes mean and what size hook is best for the particular fishing job you have in mind.
When I was a kid, I fished off a jetty in a creek in Kenya, unguided and making it up as I went along. I always thought a combination of a big hook size and lots of bait was guaranteed to succeed but I actually caught nothing.
Then a deckhand on one of the charter boats showed me the way forward and said ‘the fish you’re trying to catch have small mouths so use a very small size hook and small bait‘ – I caught 30 fish the next day
Join me as we run through everything you need to know about fishing hook sizes so that you can be sure you’re always using the right hook for the job.
In this article...
What are fishing hook sizes?
Fishing hook sizes are a rough scale that were created so that we anglers could know what fishing hook size to be at the tackle shop, which size to fish with, and which size to tell people what works for what.
You should also be aware that hook manufacturers don’t all follow the same rules when it comes to hook sizes, so a size 8/0 Gamakatsu hook won’t be the same size as a 8/0 Mustad, but they will be close-ish.
How do fishing hook sizes work?
The Scales – Fishing Hook Size and Aught
Hooks come in two scales, size and aught, and they aren’t different scales, one flows into another.
The size scale is denoted with a # and runs from a size 32# to a size 1#, 32# being the smallest and 1# being the largest. For example a size 32# hook would be used to tie the smallest dry fly in the world on – in fact it’s even smaller than that. While size 1# is about the size you would use for bluefish.
NOTEThe aught scale continues on from size 1# and it starts with a 1/0 and runs all the way up to 19/0.
Which hook size is bigger?
So which size fishing hook is bigger a 2# or a 2/0? The answer is a 2/0 since, as we discussed above, the size # scale is where hook size begins (small) and the aught scale x/0 is where it ends (big).
What do fishing hook sizes mean?
Hook sizes are not a measurement of strength or quality but a measurement of the length of the shank and how large the gap is between the hook point and the hook shank is called the Gape.
Fishing Hook Strength
Most fishing hooks do have a higher strength as their size increases, as larger hooks are made with a thicker stronger material. But, be careful as hook types by manufacturer range in strength and quality, so a Mustad hook might not be as strong as a Gamakatsu hook.
Parts Of A Fishing Hook
The hook eye is the rounded part at the top of the hook where you tie your fishing line, leader or attach a swivel.
It’s usually a closed hoop and the size of the eye increases with the size of fish hooks so that a larger line or light wire can fit through them.
The shank is the straight part of the hook that leads from the eye around the bend to where the point begins. The size of the shank increases with the size of the hook but hooks can also come in a short shank design or a long shank.
The bend of the hook is the part of the shank that bends and creates the curve that leads to the point. The bend differs depending on the type of hook as it dictates the gap or gape depending on how long or short it is.
The Gap (Gape)
The gap or gape of a hook describes the distance between the point and the shank. The gap differs based on hook type, size and purpose. Wide gap hooks help set the hook on fish with large mouths as the hook sets better in the fish’s mouth.
The barb refers to the small piece of metal that sticks out of the hook just below the point. The barb is designed to hold bait on the hook and to ensure the hook stays in a fish mouth.
Barb Vs Barbless
You can buy barbed hooks or barbless hooks, or make your hooks barbless by crimping the barb down which is what I do.
I’m a catch and release fisherman so I always fish barbless as removing a barbless hook from a fish is very easy and doesn’t require a hook remover.
TIPIf you want to make sure the fish you catch are released as healthy as possible, make sure barbless hooks are used.
The point of a hook describes the sharp part which goes into bait and into a fish’s mouth so it’s hooked when the fish eats the bait. Hook points can vary in style from spear point to needlepoint trocar, hollow, and knife edge.
NOTEThe key thing about the point is that it’s sharp as dull hooks do not catch fish!
Types Of Fishing Hooks
Having a good hook selection in your tackle box is important as one hook will suit one fishing style better than another. When using the right fishing hook, you’ll catch more fish.
Below, we run through each type of fishing hook and what they are good for so you know which ones you should have in your tackle box.
A bait hook comes with extra barbs located on the shank of the hook and these help to hold a natural bait on the hook. A bait hook is used for bait fishing with dead worms, clams, or other dead or live baits.
You can use a bait hook for both saltwater fishing and freshwater fishing. You can buy a bait hook in a large range of sizes to match the size of fish you are targeting.
Wide Gap Hook
A wide gap hook is one of the fishing hooks most used to catch bass with soft plastic baits such as soft plastic worms. The large gap allows the soft plastics to compress when bitten allowing for a better hook set when a bass eats it.
A J-hook is the most common and versatile hook in the world. The J-hook is called a “J-hook” because the hook looks like the letter J and they come in every size, material, and are used for fresh and saltwater fishing.
The J-hook is the most used of all saltwater hooks as you can use a J-hook for live bait, dead bait, in a lure offshore fishing, in a fly and for big fish.
TIPYou should always have a few J-hook sizes in your fishing box as they will get you out of a sticky situation like running out of the “right fishing hook”.
Aberdeen hooks are like a J-hook but an aberdeen hook has a longer shank than a J-hook with a short bend. The aberdeen hook is therefore easier to remove from fish with smaller mouths.
NOTEThe most popular aberdeen hooks are thus very small hooks popular with fishermen who focus on panfish like crappie and bluegill.
Circle hooks are a kind of bait hook but the difference with circle hooks is that they have a point that is curved all the way around, hence the name circle hook. A circle hook is the best bait hook to use if you want to ensure you don’t damage fish.
The way a circle hook works means it can’t hook a fish deep inside it’s throat as the point is hidden on a circle hook as it points in wards.
When a fish swallows a circle hook and you then hold the line tight, the circle hook leaves the fish’s throat and it will then hook fish in the corner of the mouth as it exits.
This makes a circle hook the number one choice for bait fishermen who use both live and dead baits as they ensure the fish are hooked in the mouth and easily released.
TIPI use these fishing hooks often when bottom fishing as they allow me to release anything I catch which wasn’t the target fish or large enough for the pot.
EWG Worm Hook
EWG Worm Hooks, meaning an extra wide gap worm hook, is similar to a Wide Gap Hook but with a much wider gap. Worm hooks are made to fish large soft plastics such as plastic worms or frogs, and come with an extra wide gap so you can still hook fish.
The extra gap on worm hooks means that when a fish bites, the worm hook gap is wide enough to allow the point of the worm hook to bed itself in the mouth of the fish.
A treble hook is formed of 3 J-hooks welded together. Treble hooks therefore come with three points, three barbs, but one eye.
You’ll find almost all jerk baits, crankbaits, top water plugs, and poppers come with treble hooks and they provide a better hook up rate since they have three points and three barbs.
Treble hooks are pretty much three hooks in one which might help you catch more fish but it makes them dangerous for both fish and anglers.
I have had a treble fish hook stuck in my hand while one of the other points was attached to a wriggling tuna – needless to say, my hand didn’t look good afterwards.
RECOMMENDATIONI would recommend removing all treble hooks and replacing them with a J-hook on all your lures.
FAQs On What Fish Hook Size To Use
How do you know what size fishing hook to use?
Picking the right size fishing hook comes down to the size of your bait and the size of the fish you are going after. You need to make sure the hook is small enough to fit inside the mouth of the fish you want to catch while being big enough to hold it correctly on your intended bait.
Another consideration is the gape of a hook, and changing it depending on the species you are going after.
For example, when fishing for GTs on fly I use 4/0 or 6/0 size hooks for their gape and strength, but for popper flies I use an 8/0 as they provide a better hook up rate when a GT eats on the surface.
NOTEUnderstanding what gape works best when comes with practice, experimentation, and time on the water.
What size hooks for what size fish?
Hooks size and fish size do not always correlate for example you can catch a huge brown trout on a size 22# dry fly and the same fish on a size 4# with a worm on it.
I also use a bigger hook to catch a GT on fly than I do for a sailfish on fly, but a sailfish is much bigger than a GT.
Generally speaking though, the smaller the fish the smaller the hook to ensure the hook will go in its mouth when it decides to eat the bait, just make sure it’s not too small that it breaks or too small a gape that it doesn’t hook up well.
For additional information about hook sizes, you can watch this video.
Thanks very much for reading my article. I hope you found it useful and now know everything about fishing hook sizes to pick the right one for the right fish and situation.
Please share the article with your fishing buddies and maybe check out some of our other articles – we cover everything from rods to reels, lures, and even fish finders.