What this calculator does
Fishing reel line capacity works out how much line of a new diameter fits on a reel, from a known spool capacity. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
The inputs explained
| Field | What to enter |
|---|---|
| Known line length that fills the spool (m) | A number, measured in m. Starts at 150. |
| Known line diameter (mm) | A number, measured in mm. Starts at 0.3. |
| New line diameter (mm) | A number, measured in mm. Starts at 0.4. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with known line length that fills the spool
Every other input is held at the calculator’s starting values while known line length that fills the spool varies. Select any row to load that scenario into the calculator.