Bolt Pattern Calculator
Calculate bolt positions, spacing, and coordinates for circular bolt patterns. Get X,Y coordinates for drilling or layout.
Pattern Parameters
Units:
4 bolts
2 bolts24 bolts
4 in
1 in20 in
in
0°
0°360°
Starting angle from horizontal (3 o'clock position)
Pattern Info:
Angle between bolts: 90.00°
Radius: 2.0000 in
Circumference: 12.5664 in
Chord Length (Bolt Spacing)
2.8284 in
Distance between adjacent bolts
⌒Arc Length
3.1416 in
⭕Circle Area
12.5664 in²
Bolt Coordinates (X, Y):
| Bolt | Angle | X | Y |
|---|---|---|---|
| #1 | 0.0° | 2.0000 | 0.0000 |
| #2 | 90.0° | 0.0000 | 2.0000 |
| #3 | 180.0° | -2.0000 | 0.0000 |
| #4 | 270.0° | -0.0000 | -2.0000 |
Usage Notes:
- - Coordinates are relative to pattern center (0,0)
- - Positive X is to the right, positive Y is upward
- - Use chord length for edge-to-edge measurement
Common Bolt Patterns
4-Bolt Pattern
90° spacing, common for flanges
6-Bolt Pattern
60° spacing, automotive wheels
8-Bolt Pattern
45° spacing, heavy-duty flanges