What this calculator does
Involute function works out finds the involute of a pressure angle, used in gear-tooth geometry: φ = tan(α) − α. 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
Formulaφ = tan(α) − α, with α (the pressure angle) measured in radians
The inputs explained
| Field | What to enter |
|---|---|
| Pressure angle α (degrees) | A number. Starts at 20. |
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 pressure angle α (degrees)
Every other input is held at the calculator’s starting values while pressure angle α (degrees) varies. Select any row to load that scenario into the calculator.