Enter the bolt diameter (in) and the threads per inch into the Bolt Area Calculator. The calculator will evaluate the Bolt Area. 

Bolt Area Formula

The following two example problems outline the steps and information needed to calculate the Bolt Area.

BA = .7854*[D-(.9734/n)]^2
  • Where BA is the Bolt Area (in^2)
  • D is the bolt diameter (in) 
  • n is the threads per inch 

To calculate bolt area, subtract the value of .9374 divided by threads per inch from the bolt diameter, square the result, then multiply by .7854.

How to Calculate Bolt Area?

The following example problems outline how to calculate Bolt Area.

Example Problem #1:

  1. First, determine the bolt diameter (in).
    • The bolt diameter (in) is given as: 3.
  2. Next, determine the threads per inch.
    • The threads per inch is provided as: 2.
  3. Finally, calculate the Bolt Area using the equation above: 

BA = .7854*[D-(.9734/n)]^2`

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

BA = .7854*[3-(.9734/2)]^2 = 4.96 (in^2)

Example Problem #2: 

For this problem, the variables required are provided below:

bolt diameter (in) = 4

threads per inch = 8

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

BA = .7854*[D-(.9734/n)]^2` = ?