Please notice: LeaderCalc hasn't been optimized for small screens. Turning some devices horizontally might make it easier to use.


Select the desired specifications for your leader and press "Find leaders" to look up suggestions.

Quick use

December 2019: The LeaderCalc pages have been slightly updated with more leaders and new facilities.
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 this new tool here.
Leadercalc currently contains 2791 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.

Randomly selected: Rajeff Bass Bug

Category: Panfish/Bass/Pike/Musky
Bass Bug leader designed by Steve Rajeff

0X - 6.5'
Show all variations

30" of 0.0280
18" of 0.0240
9" of 0.0210
6" of 0.0180 (06X)
15" of 0.0140 (02X)

Randomly selected: Panfish Delicate

Category: Panfish/Bass/Pike/Musky

7X - 10.0'
Show all variations

31" of 0.0190 (07X)
16" of 0.0170 (05X)
13" of 0.0150 (03X)
11" of 0.0130 (01X)
7" of 0.0110 (0X)
7" of 0.0090 (2X)
7" of 0.0070 (4X)
29" of 0.0040 (7X)


Since you got this far …

The GFF money box

… I have a small favor to ask.

Long story short

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Long story longer

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See more details about what you can do to help in this blog post.