|Tippet Size||Tippet Diameter||Approximate breaking strength in Super Strong nylon (pounds)||Balances with fly sizes:|
|8X||.003"||1.75||22, 24, 26, 28|
|7X||.004"||2.5||18, 20, 22, 24|
|6X||.005"||3.5||16, 18, 20, 22|
|5X||.006"||4.75||14, 16, 18|
|4X||.007"||6||12, 14, 16|
|3X||.008"||8.5||6, 8, 10|
|2X||.009"||11.5||4, 6, 8|
|1X||.010"||13.5||2, 4, 6|
|0X||.011"||15.5||1/0, 2, 4|
|.012||.012"||18.5||5/0, 4/0,3/0, 2/0|
|.013||.013"||20||5/0, 4/0,3/0, 2/0|
|.015||.015"||25||5/0, 4/0,3/0, 2/0|
How to choose the right tippet size
Choosing the right tippet depends almost entirely on the fly you choose. It’s mainly based on the size of the fly, although sometimes water clarity or the size of the fish you are after can influence the tippet size you choose—but it should still fall within the range of the fly sizes shown in the chart below.
For a fly to cast properly but still land on the water lightly, the tippet used must have the right balance of stiffness and flexibility—which comes from the diameter of the tippet used, not its pound-test or breaking strength. The tippet must be stiff enough to let you straighten your entire leader so you can place your cast accurately, but it must also be flexible enough to allow the fly to move in a natural manner. If you use too heavy a tippet your fly may not move naturally with the current or swim properly, but if it is too light the air resistance of a fly that is too big for the tippet will push back against the fly, making your leader land in a messy coil. Flies that are too big and air resistant for a tippet may also spin and twist when you cast them.
Of course, if a tippet is so large that it won’t fit through the eye of the fly you are tying on, that’s a good indication that the tippet is too big. But you can also run into problems if the tippet is too small for a given hook size. If you tie a very thin tippet to a heavy hook, when the wire diameter of the eye of the hook is a lot greater than the diameter of the tippet, your knots will slip and not hold. Thus, if you are fishing a size 16 dry fly with a 5X tippet and you decide to fish a size 6 streamer, you’ll have to go to a heavier tippet, like 2X, or your clinch knots won’t hold.
If you want to see how to modify your leader to change tippet sizes, here’s a helpful video:
Chapter Nine: Prospecting for Trout - 11. How to modify a leader.
If you’re fishing a size 16 fly, based on the chart below the middle ground for tippet size would be 5X, and that’s appropriate for most situations. However looking at the chart you can also use a lighter 6X tippet or a heavier 4X tippet. If the water is very clear or very slow, or if there are many conflicting currents that might cause a fly to drag unnaturally, you may want to switch to the lighter 6X tippet.
On the other end of the scale, if you’re fishing a choppy riffle or dirty water where the fish may not get a close look at your fly, you may be able to get away with the heavier 4X tippet. And if you expect to hook very large fish on that size 16 fly, you may want to go to 4X. You might sacrifice a bit of delicacy and might not get as many takes with the heavier tippet—but you’ll have a better chance at landing them!
There are a couple other considerations that might convince you to go to a heavier tippet size. One is water temperature. When trout streams get into the mid-60s, trout have more difficulty getting enough oxygen, and if you play them too long they may not survive. So smart anglers will go to a heavier (stronger) tippet than they would normally use (like 4X on that size 16 fly), allowing them to play fish quicker instead of playing them to exhaustion. Yes, again you might not get as many strikes but if you care about releasing fish unharmed it’s a worthwhile tradeoff.
The other time you may want to go to a heavier tippet is when the fly you choose is very air-resistant. Large articulated streamers and foam dry flies fall into this category. Thus, if you switch from a slim parachute fly to a foam-bodied pattern but both are size 16, you may wish to use a tippet one size larger to prevent the foam fly from twisting your leader when you cast it.
And, finally, if you don’t want to carry this chart around you, remember the rule of 3: Divide the hook size by 3 and you’ll get the appropriate tippet size. For example, with that size 16 fly, divide by 3 And you get 5.3333333333333. OK, so you won’t have any 5.33X tippet but 5X is plenty close enough!