Calculate the pitch diameter of gears using Diametral Pitch or Module.
Gear Specifications
Gear Dimensions
Designing Gears?
Select your system and enter gear details to find the pitch diameter.
About this calculator
Overview
The pitch diameter is the diameter of the pitch circle, which goes through the center of the gear teeth. It is the most important dimension for calculating gear ratios and center distances.
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Pro Tips
Outside Diameter (OD) is typically Pitch Diameter + (2 / P) for standard gears.
Circular Pitch (p) = π / P (Imperial) or p = π × m (Metric).
Always check if you are working with standard involute gears or modified profiles.
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Fun Facts
"Two gears must have the same Diametral Pitch (or Module) to mesh correctly."
"The pitch diameter is used to calculate the center distance between two meshing gears: C = (d1 + d2) / 2."
"In the metric system, Module is essentially the pitch diameter per tooth (mm/tooth)."
Formula: d = N / P (Imperial) or d = N × m (Metric)
