A fishing hook size chart helps anglers pick the right hook for their target species and bait. Hook sizes range from tiny #32 (used for micro flies) up to massive 20/0 (used for marlin and giant tuna). Understanding the numbering system, gap widths, and species pairings ensures your hook matches your fishing situation. Use this free interactive guide to find the perfect hook size.
Hook Size Chart
Click any row for full details
| Size | Gap (in) | Target Species | Bait Type |
|---|
Visual Size Comparison
Hooks shown at relative scale (not actual size)
Bait Pairing Guide
| Bait Type | Hook Size Range | Best Hook Type | Target Species |
|---|
How to Use the Fishing Hook Size Chart
Choosing the right fishing hook size is one of the most important decisions you make before hitting the water. A hook that is too large will spook wary fish and make it hard to present small baits naturally. A hook that is too small may not set properly in a large fish's mouth and can lead to lost catches. This interactive chart simplifies the selection process by showing every common hook size alongside gap width, species recommendations, and bait pairings.
Step 1: Select Your Target Species
Use the species selector dropdown at the top of the chart to filter hook sizes for the fish you are targeting. When you select a species like bass, trout, or catfish, the chart highlights the recommended size range and dims sizes that are too small or too large. This instantly narrows your options and shows you the sweet spot for your target.
Step 2: Choose Your Hook Type
Different fishing situations call for different hook styles. J-hooks are the traditional all-purpose design, circle hooks reduce gut hooking for catch-and-release, treble hooks are used on lures and crankbaits, and fly hooks are designed for fly tying. Use the hook type filter to see which sizes are available in each style and which types work best for your target species.
Step 3: Click a Size for Full Details
Click any row in the hook size chart to expand a detail panel showing the exact gap width in both inches and millimeters, compatible hook types, recommended species, bait pairings, and practical tips. This gives you all the information needed to make a confident purchase at the tackle shop.
Step 4: Check the Visual Comparison
The visual size comparison diagram below the chart shows a selection of hooks drawn at relative scale so you can see the size differences at a glance. This is especially helpful for understanding how much bigger a 3/0 is compared to a #6, which the numbers alone do not convey intuitively.
Understanding the Numbering System
Fishing hook sizes use two different scales. Standard sizes run from #32 (smallest) down to #1, where a larger number means a smaller hook. Aught sizes start at 1/0 and increase to 20/0, where a larger number means a bigger hook. The transition from #1 to 1/0 is the dividing line. Gap width in inches is the most reliable way to compare sizes across manufacturers, since exact dimensions can vary slightly between brands.
Matching Hook Size to Bait
The bait pairing table provides quick reference for matching your preferred bait to the right hook size. Small flies and nymphs pair with tiny hooks in the #24 to #14 range, while whole fish baits for offshore species need 6/0 and larger. The hook gap must be wide enough to accommodate the bait while leaving enough point exposed to penetrate the fish's mouth on the strike. When in doubt, err slightly smaller for finesse presentations and slightly larger for power fishing with aggressive species.
Frequently Asked Questions
Is this fishing hook size chart free?
Yes, the fishing hook size chart is completely free with no signup, no ads, and no limits. All data is loaded instantly in your browser with nothing stored or sent anywhere.
Is my data safe and private?
Absolutely. Everything runs locally in your browser using JavaScript. No personal information or usage data is collected, transmitted, or stored on any server.
How do fishing hook sizes work?
Hook sizes use two numbering systems. Standard sizes (#32 to #1) get larger as the number decreases, so a #6 is bigger than a #12. Aught sizes (1/0 to 20/0) get larger as the number increases, so 5/0 is bigger than 2/0. The crossover from #1 to 1/0 is where the system shifts.
What size hook should I use for bass?
For largemouth bass, sizes #4 through 3/0 work well depending on bait. Use #6 to #2 for worms and live bait, #2 to 1/0 for soft plastics, and 2/0 to 3/0 for larger swimbaits and frogs. Circle hooks in 1/0 to 3/0 are popular for catch-and-release bass fishing.
What is the difference between a J-hook and a circle hook?
J-hooks have a straight shank with a pointed tip aimed upward, requiring a hook set on the bite. Circle hooks curve inward toward the shank and are designed to slide to the corner of the mouth, reducing gut hooking. Circle hooks are preferred for catch-and-release fishing.
What size hook for trout fishing?
Trout hooks are typically smaller, ranging from #18 to #8 depending on the method. Fly fishing uses #18 to #12 for dry flies and nymphs. Bait fishing with worms or PowerBait uses #12 to #8. For larger lake trout, move up to #6 to #2 with larger bait presentations.
What does the gap width measurement mean?
Gap width is the distance between the hook point and the shank, measured at the widest part. It determines how large a bait can fit on the hook and what size fish mouth the hook can penetrate. Wider gaps accommodate bigger baits and are better for fish with larger mouths.
Are hook sizes the same across all manufacturers?
Not exactly. While the numbering system is universal, actual dimensions can vary slightly between manufacturers and hook styles. A #6 from one brand may be slightly different from another. The gap widths shown here are approximate industry averages to give you a reliable starting point.