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LeaderCalc

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

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.

Randomly selected: Nymph, Midge

Category: Nymph/Wet Fly Leaders
Nicely tapered and delicate leader for the smaller flies down to the 14-16-18 and smaller range.
NameSectionsTippetLengthLineFormula

5X - 10.5'
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95X
0.0060"		10.5'3-6wt.
28" of 0.0190 (07X)
14" of 0.0170 (05X)
14" of 0.0150 (03X)
7" of 0.0130 (01X)
7" of 0.0110 (0X)
7" of 0.0090 (2X)
7" of 0.0080 (3X)
7" of 0.0070 (4X)
35" of 0.0060 (5X)
Save | Labels
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Randomly selected: Tarpon

Category: Saltwater
A general but fairly long tarpon leader. We're getting out the big guns here! Notice that the tippet is extra heavy Fluorocarbon for bite resistance (Bt. = Bite tippet). Tying this bit onto the last tapered bit of the leader is usually done with a Bimini knot (AKA Bimini twist).
NameSectionsTippetLengthLineFormula

Bt. - 12.0'
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Show similar

5Bt.
0.0610"		12.0'10-12wt.
50" of 0.0330 Mason Hard
25" of 0.0280 Mason Hard
25" of 0.0240 Mason Hard
19" of 0.0200 (08X) Mason Hard
25" of 0.0610 (Bt.) Fluorocarbon
Save | Labels
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