Countersink Depth Calculator Pro (USA)
Precision Engineering & Woodworking Tool • Imperial Units
Diameter of the screw head or finished hole.
Diameter of the pre-drilled hole (shank).
Required Depth
0.000
InchesLive Cross-Section View
💡 Expert Guide: Understanding Countersink Depth
Why use this Calculator? In precision manufacturing and woodworking, guessing the depth of a countersink can lead to screw heads sitting too high (“proud”) or digging too deep (“chatter”). This tool uses the tangent trigonometry function to provide exact results instantly.
USA Standards (Imperial Units)
For users in the United States, the most common standard for Flat Head Machine Screws (ANSI B18.2.1) is 82 degrees. However, woodworking screws often utilize a 90-degree angle. Always verify your drill bit angle before calculating.
The Formula
Our calculator uses the geometric relationship:
Depth = (Major Diameter - Minor Diameter) / (2 × tan(Angle / 2))This ensures that the top of the screw sits perfectly flush with the surface of the material.
