Enter the lead of the screw and the circumference of the screw into the calculator to determine the helix angle.

Helix Angle Calculator

Defaulted to the main search intent: thread helix angle from diameter plus pitch or TPI, with a secondary helix length tool.

Thread Helix Angle
Helix Length
Use pitch diameter for the best estimate. If you only know the major diameter, switch the diameter type below.
Pitch Diameter
Major Diameter
Pitch
TPI
Degrees
Radians
Use this when the main need is the length of a helix, not the thread angle alone.
Number of Turns
Total Rise
Degrees
Radians

Helix Angle Formula

The following formula is used to calculate the angle of a helix screw. 

HA = atan(L / C)
  • Where HA is the helix angle
  • L is the lead of the screw
  • C is the circumference of the screw

To calculate a helix angle, take the inverse tangent of the result of the lead of the screw divide by the circumference of the screw.

Helix Angle Definition

A helix angle is an angle formed by the shape of a screw, which is governed by its overall circumference and its lead.

The lead is a measure of the linear distance a nut will travel with one revolution around the screw.

Example Problem

How to calculate helix angle?

The following example outlines the steps and information needed to calculate the angle of a helix.

First, determine the lead of the screw. The lead of the screw in this example is .25 inches.

Next, determine the circumference of the screw. The circumference for this problem is measured to be 3 inches.

Finally, calculate the helix angle using the formula above:

HA = atan(L / C)

HA = atan(.25/ 3)

HA = 4.755 degrees