Nineteen free tools, all built on published tackle specifications. Each one answers a single question you would otherwise guess at on the water — no signup, no email, no limits.
| If you are… | Start with | Then |
|---|---|---|
| Buying your first setup | Lure Weight Calculator | Line capacity, then the beginner tackle kit |
| Spooling a reel | Reel Line Capacity Calculator | Braid to mono for backing, then how to spool |
| Setting drag | Drag & Leader Calculator | Knot strength — the knot is where it breaks |
| Losing fish | Knot Strength Calculator | Line strength chart to check the line class |
| Fishing deep structure | Jig Head Weight Calculator | Crankbait depth chart |
| Casting for distance | Casting Distance Calculator | Rod length chart, then the shock leader for heavy payloads |
| Fishing a depth you cannot see | Lure Sink Rate Calculator | count the lure down, then check the water temperature for where fish are holding |
Every tool here works the same way: you enter what you already know, it works out what you need, and it prints the formula it used so you can check the arithmetic. Four steps cover almost every case.
Do not start from the gear you happen to own. Start from the problem. "How heavy a lure can this rod cast" is the lure weight calculator. "How much line fits this spool" is reel line capacity. Two calculators can accept the same input and answer different questions, so the question has to come first.
Measured values beat printed ratings. A rod stamped 10-20 lb gives you the rating, not the rod in your hand. If a tool asks for line diameter and you only know the test strength, run the line diameter converter first and come back. An estimated input produces a confident-looking answer built on an estimate.
Each tool states what it assumes: a knot efficiency percentage, a spool fill factor, a sink rate measured in still water. Those assumptions are printed beside the result on purpose. When your situation differs, the number moves. Treat these outputs as a comparison between setups rather than a prediction of one cast or one fish.
Reading lb test as line diameter. Setting drag as a percentage of braid strength without allowing for the leader. Treating a manufacturer capacity figure as exact when it was measured with a different braid. Entering rod length in feet where the field expects inches. If a result looks wrong, one of these four is usually the reason.
They rarely do, because the shared tables are the same tables: the diameter behind the braid converter is the diameter behind the drag calculator. A mismatch almost always means two different inputs went in, not that one tool is wrong. Compare the inputs before you compare the answers.
Every calculator accepts US customary units, and most show a metric equivalent beside the result. Conversions follow the NIST (National Institute of Standards and Technology) SI conversion factors. Switching between pounds and kilograms partway through a calculation is the most common source of an answer that looks plausible and is not.
Not every question needs a calculator. These pages are reference tables you can read straight off the screen — line strength, reel sizes, rod lengths, leader sizes, crankbait depths, fish weights by species, water temperature by species, swivel sizes and split shot sizes.
For the buying decisions behind the numbers, the guides index collects all of them in one place.
All charts and guides · Beginner tackle kit list · Rod power and action · About TackleCalc
Yes. Every tool on this site is free, works without an account, and does not ask for an email address. There is no signup and no limit on how many times you use them.
Published tackle specifications and standards: AFTMA line weights, JAFTMA braid diameters, manufacturer capacity ratings, state fisheries formulas, and the published one-third drag rule. Where sources disagree we show the range instead of picking one.
Yes. Every calculator is a single page with no dependencies, and the results are designed to be read on a phone while you are on the water.
Yes, deliberately. The line diameter table used by the diameter converter is the same one behind the braid converter and the drag calculator, so a number you get in one tool matches the number you get in another.
Disclaimer: The numbers on this page are estimates based on published specifications and standard formulas. Real-world results vary with brand, gear condition and how the equipment is set up. TackleCalc is an independent reference site and is not affiliated with any manufacturer. Nothing here replaces the instructions that come with your own gear.