Machining calculator

Machining Bolt Pattern

Compute the bolt-pattern circle diameter from center-to-center measurements.

Inputs

Fill in your scenario

Result

Computed for your scenario

Bolt circle (mm) 0
Radius (mm) 0
FAQ

Common questions

What if I have an even number of bolts?
Measure across the bolt pattern from center of one bolt to center of the opposite one — it equals the BCD directly.