Enter the total length of the screw and the total number of threads into the calculator to determine the thread pitch and threads per distance.

Thread Pitch Formula

The following formula is used to calculate the total thread pitch.

P = 1/n
  • Where P is the thread pitch (in)
  • n is the number of threads per inch

To calculate the thread pitch, take the inverse value of the number of threads per inch.

Thread Pitch Definition

What is a thread pitch? A thread pitch is defined as the total distance between threads in a screw or any other object with helical spirals.

Example Problem

How to calculate a thread pitch?

  1. First, determine the total length of the screw.

    For this example, the screw is 12 inches long.

  2. Next, determine the total number of threads on the screw.

    Once counted, we find that there are 24 threads.

  3. Next, determine the threads per inch.

    Dividing the number of threads by the total length, we get a threads per inch of 2.

  4. Finally, calculate the thread pitch.

    Using the formula P=1/n we find the pitch to be 1/2 = .5 inches.


Is thread pitch metric? Thread pitch can be described using metric or imperial units. The definition of thread pitch is only the inverse of the threads per distance, therefore, it does not require a specific unit of measure.

Can you change the thread pitch? In order to change a thread pitch, you must change both the screw thread and mating thread in the hole so that they match and have the same pitch. They will not fit properly with different pitches.

Should I use a course of fine thread pitch? Course thread pitches provide more resistance to stripping and they install faster. If these are important considerations in your design, you should use a coarse thread. Fine threads provide for strength but take longer to install. If strength is the most important factor, fine thread pitch should be used.