How to Select Fly Lines for Single/Two-handed Fly Rod? AFFTA Chart (former AFTMA)

2012/6/2 How to Select Fly Lines for Single/Two-handed Fly Rod? AFFTA Chart (former AFTMA)

Fly fishing puts the most importance in casting than any other form of fishing and correct selection of fly line is critical in providing distance, accuracy, or even comfort when fishing over hours. So, how to choose the correct line for your fishing?

1. We Are Casting “Head” of Fly Line

The fact is fly rod is engineered just as any other rod to cast the load of something. In our case, it happens to be the head part of fly line. That’s it. All you need is to match the weight of head of fly line, which is what you are actually casting, to the potential energy designed for the rod.


What if the weight of the head exceeds your rod? No problem. You can keep “shorter” length of fly line out of your rod tip to keep the total mass adjusted to the power of your rod. Or you can Just snip it off until it is the correct weight to fit within your rod’s weight allowance. Otherwise, take the chance and see what happens. Every rod has a buffer for 30-50 grains higher or lower.

2. Single-Hand Fly Rod & Fly Line

In single-hand fly rod, line weight is always measured at the first 30 feet forming the head of fly line excluding tip section. It is quite simple one-to-one chart between your single-handed fly rod and fly lines. You probably don’t even have to remember the grain/gram part, if you’re only fishing in river for normal circumstances.

Number Designation Grain Weight Margin for Error Gram Weight
1-Weight 60 54-66 3.9
2-Weight 80 74-86 5.2
3-Weight 100 94-106 6.5
4-Weight 120 114-126 7.8
5-Weight 140 134-146 9.1
6-Weight 160 152-168 10.4
7-Weight 185 177-193 12.0
8-Weight 210 202-218 13.6
9-Weight 240 230-250 15.6
10-Weight 280 270-290 18.1
11-Weight 330 318-342 21.4
12-Weight 380 368-392 24.6
13-Weight 450 29.2
14-Weight 500 32.4
15-Weight 550 35.6

However, when you need to use sinktip that adds extra weight to your shooting head or using heavy fly which produces more air drag, you should keep it in mind making the whole thing from fly to your fly line in correct weight. And you cast with ease.

Single-Hand Shooting Head for Overhead Cast

When selecting shooting head, you should select the same weight shooting head as the specification of your rod. You can, however, put shooting head +1wt ONLY when you want to use more power to turn over your air resistant fly such as floating baitfish or drake pattern. This is called “over-lining”.

Single-Hand for Spey/Skagit Cast

Also, if you want to execute spey cast using single-handed rod, you can over-line by 2wt, for instance, use 3wt fly rod with 5wt line. But in reality, 30feet head is too long to handle on single-hand rod designed between 7-9 feet long, so you need to select line that is 3wt heavier then snip the excess part off.

Otherwise, there are ready-made skagit shooting head from RIO and OPST which come in short length. Because they are skagit head, you need to add polyleader or sinktip to make part of your line system keep touching water to act as an anchor.

For instance, I am matching my old R.L. Winston LT 3wt with OPST 150 grain skagit Commando Head with long enough polyleader to load the rod not designed for spey cast whatsoever that can now cast 60-80ft with no back cast.


3. Two-Handed Fly Rod & Fly Line

When you walk into the world of two-handed fly rod from ordinary single hand background, you will be lost in confusion over selecting right fly line. First clue is to know what style your two-hand rod is designed for.

  • Spey – Also known as “traditional”. Only type that use long belly and mid belly line
  • Scandinavian – Shooting head for waterbourn cast. You change the whole shooting head when selecting to fish different sink rate
  • Skagit – Shooting head for waterbourn cast. Skagit uses one shooting head that is shorter than Scandinavian then attach interchangable tips to fish different sink rate
  • Overhead – Shooting head fit to maximize distance when cast overhead

Second clue is to know how to much weight your rod is engineered to allow. Then use below chart as guideline to select the correct fly line of your choice.

Type of Line Shooting Head for overhead cast Short Belly or Scandinavian Head Medium Belly – Spey Long Belly – Spey
Length of Belly 30-50′ 50-60′ 60-70′ 70’+
Weight Measured at 40′ 55′ 65′ 80′
6wt 250 grain/16.2g 420 grain/27.3g 460 grain/29.9g 600 grain / 39.0g
7wt 300 grain/19.5g 470 grain/30.5g 510 grain/33.1g 650 grain/39.0g
8wt 360 grain/23.4g 530 grain/34.4g 570 grain/37.0g 710 grain/46.1g
9wt 430 grain/27.9g 600 grain/39.0g 640 grain/41.6g 780 grain/50.6g
10wt 510 grain/33.1g 680 grain/44.2g 720 grain/46.8g 860 grain/55.8g
11wt 600 grain/39.0g 770 grain/50.0g 810 grain/52.6g 950 grain/61.7g
12wt 700 grain/45.5g 870 grain/56.5g 910 grain/59.1g 1050 grain/68.2g
Two-Hand for Scandinavian Shooting Head (Spey with shooting head)

It’s very similar to single-hand situation that you should select shooting head 2wt heavier than the specification of your rod. If your two-hand rod is 8wt, you need Scandinavian Head of 530 grain to make enough load when forming D-loop.

American Fly Fishing Trade Association