And you seem to indicate that you already have the information in fields... hence, no coding needed, no application development needed, just use the field calculator
http://desktop.arcgis.com/en/arcmap/latest/manage-data/tables/fundamentals-of-field-calculations.htm
and Pythagorean theorem to the rescue... assuming you can calculate the difference in the x and y coordinates from the fields. If you don't have them, then you can actually calculate the same values using the field calculator and retrieving the start and end points using arcpy in the field calculator.