PCD Calculator

Calculate hole coordinates on a Pitch Circle Diameter (PCD).

Inputs

Angle of the first hole relative to the positive X-axis (counterclockwise).

Diagram

Results
Calculated Hole Coordinates (X, Y)
  • Hole 1: (50.000, 0.000)
  • Hole 2: (25.000, 43.301)
  • Hole 3: (-25.000, 43.301)
  • Hole 4: (-50.000, 0.000)
  • Hole 5: (-25.000, -43.301)
  • Hole 6: (25.000, -43.301)
More Information

What is PCD?

PCD stands for Pitch Circle Diameter. It is the diameter of an imaginary circle that passes through the center of all the holes in a circular pattern, typically used for mounting wheels, flanges, or other components.

Calculation Formula

The coordinates (X, Y) for each hole are calculated using trigonometry based on the PCD, number of holes, and start angle. The angle for each hole θᵢ (where i is the hole index starting from 0) is determined by dividing 360 degrees by the number of holes and adding the start angle offset.

Angle (θi)

θi = Start Angle + i × (360° / N)

Where N is the Number of Holes.

X Coordinate (xi)

xi = Cx + (PCD / 2) × cos(θi)

Where Cx is the Center X coordinate.

Y Coordinate (yi)

yi = Cy + (PCD / 2) × sin(θi)

Where Cy is the Center Y coordinate.

Assumptions & Notes

  • Holes are assumed to be equally spaced around the PCD.
  • The start angle is measured counterclockwise from the positive X-axis.
  • The hole diameter input is used solely for visualization purposes in the diagram and does not affect the coordinate calculations.
  • Common applications include mounting wheels on vehicles, attaching pipe flanges, and positioning components on gears or pulleys.
  • For calculations involving trigonometric functions (like `cos` and `sin`) in most programming libraries, the angle (θᵢ) must be converted from degrees to radians: Radians = Degrees × (π / 180).
  • The required precision for coordinates can vary depending on the application; use the decimal places selector to adjust the output format.