Countersink Depth Calculator
Determine countersink depth for flat head screws using head angle and diameter so fasteners sit flush without over‑cutting. Supports common angles (82°, 90°, 100°) and metric/imperial.
Units:
Mode:
mm
mm
Formulas
Depth = (H − D) / [ 2 × tan(A/2) ]
Head diameter = D + 2 × Depth × tan(A/2)
Where: H = head (major) diameter, D = hole diameter, A = included countersink angle.