LeaderCalc is a program that allows you to take an original leader formula and instantly re-calculate it for an alternate length or tippet size. For example, using the original formula measurements, you can recalculate George Harvey's 10-foot formula to an 8- to 11-foot formula in 4X-7X tippets. You will need Microsoft Excel 95 or newer to use LeaderCalc. If you don't have access to Microsoft Excel you can still download a PDF copy of the 50 leader formulas.

With this program you can alter the formulas to your liking by adjusting variables like the tippet size and overall length. Each leader will have a range of diameters and lenths that it is designed for. Leader lengths are listed on the left. The yellow fields at the right denote the tippet ranges for the formulas. By using the three menus at the top of the chart (leader length, tippet size, and line weight) you can change the lengths and diameters of the formulas within their parameters. If you select an option outside the length or tippet ranges of a formula, the fields will be blank.

There are some things to keep in mind. Click "enable macros" when the program opens in Excell. The opening page has links to a help page, an email address for Steven Schweitzer (the designer of LeaderCalc) and a link to his website, the Global Fly Fisher. The five tabs along the bottom of the window will lead you to different feature of the program. To use LeaderCalc, click on the tab that says LC-FFMedition. To create packaging labels for your leaders, click on Label Generator. To record some notes or descriptions of popular formulas for future reference, click on Leader Information. For a list of various monofilaments and thier test strength, click on the Mono Strength Test Chart.

CLICK HERE to download a version of LeaderCalc.

CLICK HERE to download a PDF of 50 leader formulas.