Pitch Diameter Calculator
Result
Pitch Diameter Calculator Calculate the pitch diameter of gears (by tooth count and diametral pitch) or threaded fasteners. — free online calculator.
Formula
- Pitch Diameter Calculator calculates its result from Periods, Dp, Od, Tpi, Pitch. It uses the formula Gear: PD = N / DP; UN thread: PD = OD − 0.649519/TPI; Metric: PD = OD − 0.649519×pitch. Change any input to recalculate the result instantly.
- The main inputs are Periods, Dp, Od, Tpi, Pitch. Enter them in the units and format shown in the calculator.
- Keep measurements and project assumptions consistent before comparing or combining values.
- Changing any input above recalculates the result with the same calculation engine used by this page.
Example: Pitch Diameter
- Periods: 2
- Dp: 3
- Od: 4
- Tpi: 5
- Pitch: 6
Using Periods = 2, Dp = 3, Od = 4, Tpi = 5, Pitch = 6, the calculated result is 0.102886.
Sample result: Calculating…
Frequently asked questions
What does the Pitch Diameter calculate?
Pitch Diameter Calculator Calculate the pitch diameter of gears (by tooth count and diametral pitch) or threaded fasteners. — free online calculator.
Which values should I enter?
Enter Periods, Dp, Od, Tpi, Pitch using the units and format shown beside each field.
What formula does this calculator use?
The calculator uses the following relationship: Gear: PD = N / DP; UN thread: PD = OD − 0.649519/TPI; Metric: PD = OD − 0.649519×pitch.
Why might my result differ from another source?
Results can differ when another source uses different units, rounding rules, conventions or assumptions. Compare the inputs and definitions before comparing results.
Does the result update automatically?
Yes. Changing an input updates the result using the same calculation engine shown on this page.