Bolt Circle Calculator ToolBy / Bolt Circle Calculator Bolt Circle Calculator Number of Bolts: Select Unit: Millimeters (mm) Inches Centimeters (cm) Choose Formula: Formula 1: Based on Bolt Hole Diameter Formula 2: Based on Chord Length Bolt Hole Diameter (Formula 1): Chord Length (Formula 2): Calculate Bolt Circle Diameter Note: Choose either the Bolt Hole Diameter or Chord Length input based on your selected formula.
