Fly-Tying Hook Size Guide
Sit down at the vise with the right hook. Pick the fly style you're tying to see the usual hook size range plus the thread and hackle that go with it.
Start every fly on the right hook
The hook is the foundation a fly is built on. Its size sets the proportion of everything else — body length, hackle, wing — and its wire gauge decides whether a dry floats or a nymph sinks. Get the starting size right and the rest of the recipe falls into place; start on the wrong hook and the fly fights you the whole way.
Fishing what you tie? Match your leader and presentation with the Lure Color Selector for the water you'll be on, and plan live bait for the same trip with the Bait Quantity Planner.
Frequently Asked Questions
How do hook sizes work for fly tying?
Fly hooks follow the standard angling convention where a higher number is a smaller hook — a #22 midge hook is tiny, while an aught size like #2/0 is large. Within a pattern family there's a usual range: dry flies commonly run #12–#18, streamers #2–#8, midges #20 and smaller. This guide gives the typical starting range for each style, plus the thread and hackle that pair with it.
How do I match thread and hackle to the hook?
Finer flies want finer thread so you don't crowd the eye or build bulk — 8/0 (70 denier) for dries and nymphs, down to 10/0–14/0 for midges, and heavier 3/0–6/0 for streamers and saltwater flies that must lock in bulky materials. For hackle, a rough guide is to match the barb length to about one and a half times the hook gap on a dry fly; soft-hackle wets and streamers use longer, webbier feathers for movement.
Are these sizes strict rules?
No — they're widely published starting points, not laws. Local hatches, the fish you're chasing, and the exact recipe all shift the numbers, and plenty of great flies break the mould. Use the chart to stock hooks and materials for a pattern family, then adjust to the naturals in front of you.
Why does the same pattern come in so many sizes?
Because you're imitating living forage that varies through the season. A mayfly dry might be a #14 in spring and a #18 by late summer as the bugs get smaller; a baitfish streamer scales up or down with the size of the local shad or minnows. Tying a pattern across its range lets you match the hatch instead of forcing one size to do everything.
A curated starting guide for fly-tying sizes, not a strict standard. Local hatches and specific recipes will shift the numbers.