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: Panfish Sturdy

Category: Panfish/Bass/Pike/Musky

5X - 8.5'
Show all variations

32" of 0.0180 (06X)
19" of 0.0160 (04X)
13" of 0.0140 (02X)
6" of 0.0120 (00X)
6" of 0.0100 (1X)
6" of 0.0080 (3X)
19" of 0.0060 (5X)

Randomly selected: Bonefish, Mono to Fluorocarbon

Category: Saltwater
A sturdy bonefish leader tied with flourocarbon in the tip section - the last leader section and tippet.
Flourocarbon is less visible, softer, stronger and more abrasive resistant than mono and great for stealthy presentations.
Aim for tippet material with a breaking strength of about 12-15 lbs.

1X - 9.5'
Show all variations

29" of 0.0210
14" of 0.0190 (07X)
29" of 0.0150 (03X)
29" of 0.0130 (01X)
14" of 0.0110 (0X)


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