How to use
Enter bolt circle diameter in mm, an integer hole count from 1 to 360, and starting angle in degrees. The centre is (0, 0), zero points along +X, and positive angles run counterclockwise.
Example calculation
For a 100 mm circle, 6 holes and a 0° start, the radius is 50 mm. The first two hole centres are approximately (50, 0) and (25, 43.301) mm.
Calculation method
r = D / 2; θᵢ = θ₀ + 360°i / N; xᵢ = r cos θᵢ; yᵢ = r sin θᵢ; i = 0 … N − 1
Calculation limits
Holes are spaced at equal angles around the circle. Results are hole centres; they do not define hole diameters, tool compensation, work offsets or machine movements.