Enter the diameter of the countersink and the angle into the calculator to determine the depth.

Countersink Depth Formula

The following formula is used to calculate the depth of a countersink. 

CD = (D/2)/tan(A/2)
  • Where CD is the countersink depth
  • D is the diameter of the countersink
  • A is the angle of the countersink (degrees)

To calculate the depth of a countersink, divide the diameter by 2, then divide again by the tangent of half of the angle of the countersink.

What is the depth of a countersink?

The depth of a countersink depends don’t the diameter of the countersink and the angle. The depth is typically considered as the vertical distance from the opening of the countersink to the “tip”.

This tip is the point at which the countersink comes together. While many countersinks are made in addition to holes, the depth is still considered from the opening to the theoretical point it would meet given its angle.

How to calculate a countersink depth?

Example Problem:

The following example outlines how to calculate the depth of a countersink.

First, determine the diameter of the countersink. In this example, the diameter is determined to be .250″.

Next, determine the angle of the countersink. The angle for this countersink in particular is 75 degrees.

Finally, calculate the countersink depth using the formula above:

CD = (D/2)/tan(A/2)

CD = (.250/2)/tan(75/2)

CD = .1629 inches