Calculate Cartesian coordinates for bolt circles with up to 100 holes. Can solve for unknown BC (Bolt Circle), HD (Hole Diameter), or MD (Measured Distance edge-to-edge).
| Hole # | Angle (θ) | Angle (DMS) | X Coordinate | Y Coordinate |
|---|---|---|---|---|
| 1 | 0.0000° | 0° 0' 0.0" | 2.0000 | 0.0000 |
| 2 | 90.0000° | 90° 0' 0.0" | 0.0000 | 2.0000 |
| 3 | 180.0000° | 180° 0' 0.0" | -2.0000 | 0.0000 |
| 4 | 270.0000° | 270° 0' 0.0" | -0.0000 | -2.0000 |
Bolt Circle Radius: R = BC / 2
Step Angle: Δ = 360° / N
Center-to-Center Chord: chord_center = 2R × sin(Δ/2)
Edge-to-Edge Distance: MD = chord_center - HD
Hole Coordinates:θᵢ = θ₀ + (i-1)×Δ, xᵢ = R × cos(θᵢ), yᵢ = R × sin(θᵢ)
D.R.O. Mode: Y coordinates are inverted (Y_dro = -Y) to match Digital Readout conventions
Usage: Enter at least two values (including number of holes). The calculator can solve for BC, HD, or MD when the other values are known. For example: if you measure the distance between hole edges (MD) and know the hole diameter (HD), the calculator will determine the bolt circle diameter (BC).