Anchor Bolt Circle Calculator

For a four-bolt square pattern, enter one center-to-center field measurement to determine the existing bolt circle diameter.

1. Select your measurement

2. Enter the on-center distance

Measure from the center of one anchor bolt to the center of the adjacent bolt.

Bolt circle diameter (BCD)

—

Enter a measurement above.

Four-bolt square pattern A circular bolt circle with four bolts, showing side-to-side and diagonal center measurements. SIDE TO SIDE DIAGONAL BCD