FREE TOOL

Bolt Circle Calculator

Calculate the X/Y coordinates of bolt holes evenly spaced around a pitch circle. Enter diameter, number of holes, start angle (°), and optional center offset — get a live SVG preview and export a CSV for CNC or inspection use. Unit-agnostic.

HOW IT WORKS

  1. Enter the bolt circle diameter — the pitch circle diameter (PCD) in any unit (mm, in, etc.).
  2. Set the number of holes — holes are spaced evenly at 360° / N.
  3. Adjust start angle and center — start angle offsets the first hole; center X/Y shifts the origin.
  4. Read the coordinate table — each row shows the hole number, angle, X, and Y coordinate.
  5. Export CSV to load coordinates into your CNC program, CMM, or inspection sheet.
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Bolt Circle Calculator
Compute X/Y coordinates of bolt holes evenly spaced around a pitch circle. Unit-agnostic — works in mm, inches, or any unit.
123456
HoleAngleXY
10.00°50.00000.0000
260.00°25.000043.3013
3120.00°-25.000043.3013
4180.00°-50.00000.0000
5240.00°-25.0000-43.3013
6300.00°25.0000-43.3013
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