Enter the drill diameter (in) and the tip angle (degrees) into the Drill Tip Length Calculator. The calculator will evaluate the Drill Tip Length. 

Drill Tip Length Formula

The following two example problems outline the steps and information needed to calculate the Drill Tip Length.

DTL = D/2/Tan(A/2)
  • Where DTL is the Drill Tip Length (in)
  • D is the drill diameter (in) 
  • A is the tip angle (degrees) 

To calculate a drill tip length, divide the diameter by 2, then divide again by the value of the tangent of half the tip angle.

How to Calculate Drill Tip Length?

The following example problems outline how to calculate Drill Tip Length.

Example Problem #1:

  1. First, determine the drill diameter (in).
    • The drill diameter (in) is given as: 5.
  2. Next, determine the tip angle (degrees).
    • The tip angle (degrees) is provided as: 30.
  3. Finally, calculate the Drill Tip Length using the equation above: 

DTL = D/2/Tan(A/2)

The values provided above are inserted into the equation below and computed.

DTL = 5/2/tan(15deg) = 9.33 (in)

Example Problem #2: 

For this problem, the variables required are provided below:

drill diameter (in) = 6

tip angle (degrees) = 45

Test your knowledge using the equation and check your answer with the calculator..

DTL = D/2/Tan(A/2) = ?