Tippet Size: What 3X, 4X, 5X, and 6X Mean
What 3X, 4X, 5X, and 6X actually measure, which one matches a fly, and how long a piece to tie on.
From the book Fly Fishing for Nerds — $9.74 →
Tippet is the replaceable piece between the end of the leader and the fly. Fly changes and break-offs consume it, and the tapered leader stays intact. The X on the spool is a diameter, and a smaller X is thicker. 3X is thicker than 6X.
The diameter in inches is 0.011 minus the X number times 0.001. A 5X is 0.011 minus 0.005, which is 0.006 inches. Across the four sizes: 3X is 0.008 inches, 4X is 0.007, 5X is 0.006, and 6X is 0.005. The pound number printed beside the X is the breaking strength of that spool. Nylon and fluorocarbon of the same X can differ, and so can two brands. Read the spool you are holding.
What you need
The chart on this page is 3X, 4X, 5X, and 6X. These two packs cover those four spools. The 9-foot 4X and 5X leaders are what you tie them to.
- RIO Powerflex tippet, 3X–5X RIO
Three 30-yard nylon spools: 3X, 4X, and 5X. 4X and 5X cover a first day. 3X is the starter Woolly Bugger.
- RIO Powerflex tippet, 4X–6X RIO
Three 30-yard nylon spools: 4X, 5X, and 6X. 5X is the usual small dry. 6X is a size 18 in clear water.
- RIO Powerflex 9-foot 4X leader RIO
Two 9-foot 4X trout leaders. The 9-foot 5X is the finer one for smaller flies.
- RIO Powerflex Plus 9-foot 5X leader RIO
A 9-foot 5X with a pre-tied loop. Use it for smaller dries and nymphs.
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1. Divide the hook size by 3
A rule of thumb: divide the hook size by 3. The result is about the X size. A size 12 hook is 4X. A size 16 is about 5X, because 16 divided by 3 is 5.3. A size 18 is 6X. When the result falls between two spools, both will fish. Use the thicker one for a heavy fly, for wind, or when you have split shot on. Use the finer one for a small fly in low, clear water.
The chart applies that rule to the starter flies. Woolly Bugger sizes (8 to 10) and Pheasant Tail sizes (14 to 18) are the ones listed on the gear page. A size 8 is about 2.7 and a size 10 is about 3.3, so both land on 3X. The Parachute Adams and the Elk Hair Caddis have no size on that page. Read the size on the fly you bought, then take the matching row.
| Tippet | Diameter | Fly size (hook ÷ 3) | Starter fly |
|---|---|---|---|
| 3X | 0.008 in | 8–10 | Woolly Bugger, sizes 8 to 10 |
| 4X | 0.007 in | 12 | A size 12 fly |
| 5X | 0.006 in | 14–16 | Pheasant Tail in 14 and 16. A Parachute Adams or Elk Hair Caddis in those sizes. |
| 6X | 0.005 in | 18 | Pheasant Tail in 18. A dry fly in size 18. |
A size 14 Pheasant Tail divides to about 4.7, so the chart lists it on 5X. In fast water, or with a little weight, 4X is the sturdier neighbor. If the only spool in your pocket is 5X, a size 18 fly will still fish. Move to 6X when refusals in clear water look like the trout saw the tippet. Tippet heavier than 3X (0X, 1X, 2X) is for bigger streamers than the starter Woolly Bugger. It can wait.
2. Stay within one size of the leader
A tapered leader already ends at the X on the package. Add tippet of that same size, or one size finer. A 5X leader takes 5X or 6X tippet. A 4X leader takes 4X or 5X. Stepping from 4X straight to 6X hinges at the knot, and the fly turns over badly. The 9-foot 4X and 5X leaders, and the matching spools, are the start in the first-rod guide and on the gear page. Add 3X when you fish the Woolly Bugger. Add 6X when the flies are size 18 and the water is clear.
Nylon sits up a little more, which helps a dry fly. Fluorocarbon sinks, which helps a nymph under an indicator. The X scale is the same on both. The knot at the leader tip is a double surgeon's, or a blood knot when the diameters are close. Fluorocarbon often wants a third surgeon's turn. The steps are the knots guide.
3. Tie on about two feet
For a dry fly, or a nymph in ordinary trout depth, cut about two feet of tippet: 20 to 24 inches. Tie it to the thin tip of the leader. A knot partway up the taper leaves you with a leader that no longer tapers. Two feet covers several fly changes. Each knot and trim uses a few inches. When about a foot is left, tie on a fresh piece. Once you are cutting into the tapered leader, you are shortening the part that turns the fly over.
On an indicator rig, tippet length is also the depth. If the fly needs to ride three or four feet down, two feet is short. Cut the length the depth calls for. That guide starts near one and a half times your depth estimate. Extra tippet beyond what the drift needs tangles in the guides and the grass. Nip the tags short.
4. Change it when you can name the reason
Replace the piece when it is nicked, wind-knotted, or frayed, and after a fish if the knot looks chewed. Stiff, cloudy tippet has had too much sun. Cut a fresh length from the spool.
Change the X when the hook size changes, or when a clean drift in clear water draws a refusal and you can see the tippet lying on the film. A dragging drift, an unread lane, or a fly that never got down calls for a different fix. Change the fly with the no-hatch guide. Change the tippet here.
5. Write the X down with the fly
One line in your phone: fly, hook size, tippet X, and whether the fly turned over or you broke off. After a few trips the note shows whether 6X fixed a visibility problem or cost you fish on the hook set.
Leaders, tippet, and matching them to the fly get more room in Fly Fishing for Nerds: A Data-Driven Guide to Finding, Hooking, and Landing Trout. Readers can take 25% off ($9.74) with code NERDS25 at https://leanpub.com/flyfishingfornerdsadata-drivenguidetofindingfishfly-fishing-for-nerds/c/NERDS25.
Run the Riverbank Checklist on the bank before you start tying knots.