LeaderCalc

Please notice: LeaderCalc hasn't been optimized for small screens. Turning some devices horizontally might make it easier to use, but using a suitably large screen is the best solution.
Select the desired specifications for your leader and press "Find leaders" to look up suggestions.
Reset

Quick use

The most advanced and comprehensive fly fishing leader tool online ... well, basically anywhere!

Using the form above you can ask LeaderCalc to caculate and show you a number of fly fishing leader formulas meeting your selected criteria. You can read more about the selection tool here.
LeaderCalc currently contains 2973 leaders for fly fishing, so there are enough to choose from.

Below you see a couple of randomly selected knotted, tapered leader formulas. Click on the name, category or other elements to see more.

Category: Dry Fly Leaders
These formulas were kindly provided by Swedish Johan Allgén. They were measured from two original HL Leonard Rod Co hand tied leaders. The sections were slightly uneven, but roughly followed the form: 18-18-18-18-20-20 inches. The leaders were labeled 9', but were more like 9.5' including a perfection loop in the butt end.

1 variation, 4X, 9.5'

Name Sections Tippet Length Line Formula

Leonard Positive Turn-Over


Show this only
Show similar
 6 4X
0.0070"		 9.5' 4-6wt.
18" of 0.0210
18" of 0.0170 (05X)
18" of 0.0150 (03X)
18" of 0.0130 (01X)
20" of 0.0100 (1X)
20" of 0.0070 (4X)
Category: Dry Fly Leaders
Save | Print labels
Category: Modern nymphing leaders
A long but fairly simple leader of equal pieces in the taper, and a very long tippet, which can vary from 5X to 8X

1 variation, 5X, 23.9'

Name Sections Tippet Length Line Formula

Boisson’s Leader


Show this only
Show similar
 6 5X
0.0060"		 23.9' 3-5wt.
35" of 0.0160 (04X)
35" of 0.0140 (02X)
35" of 0.0120 (00X)
35" of 0.0100 (1X)
35" of 0.0070 (4X)
110" of 0.0060 (5X)
Category: Modern nymphing leaders
Save | Print labels
Calculating...
Selecting all leaders will show you more than 2,500 leaders. Please narrow your criteria
Selecting All for two or more of your criteria can result in a lot of leaders and can potentially take some time to find. Consider narrowing your search... or just give it a go!

Since you got this far …


The GFF money box

… I have a small favor to ask.

Long story short

Support the Global FlyFisher through several different channels, including PayPal.

Long story longer

The Global FlyFisher has been online since the mid-90's and has been free to access for everybody since day one – and will stay free for as long as I run it.
But that doesn't mean that it's free to run.
It costs money to drive a large site like this.
See more details about what you can do to help in this blog post.