The Shaft Alignment means adjustment of the relative position between two connected machines, e.g. motor & pump or the center lines of rotation of two (or more) machinery shafts are in line with each other when the machines work under normal working conditions / temperature. Objective of shaft alignment is to increase the operating life span of rotating machinery. It' s can be decreased vibrations and wear levels in machine casings, bearings housings, and rotors, decreased energy costs & number of unplanned breakdown.Common methods to perform shaft alignment are rim / periphery and gap reading of pair coupling hub with dial indicator and digitally laser alignment.This calculator based on formulas from rim / periphery and gap reading of pair coupling hub with dial indicator. To perform shaft alignment mostly consuming time to moving the machinery to align the shafts, with this calculator can assist to calculate the result of alignment more quickly and precision. Repeat shaft alignment procedures with calculator until the result of alignment within acceptable alignment tolerance .