In the calculator, a 'Labor e' row is where an 'estimate' of total labor costs and fraction of labor to be moved are input. For Apple, an article at Investopedia, shows labor is estimated to be $5, and material is $219. To get your estimate of total labor cost, you need to calculate 5/(5 + 219)*COR on your own. COR is Cost of Revenue. For Apple this calculation yields $2.933B. The fraction of labor to be moved is the fraction of U.S. sales over total sales. There is also a 'wage/hr $' row for entering the differing wages between the two countries. (U.S. $20/hr, China $4/hr, Mexico $4/hr.) A special row is 'factory adj' for a multiple of labor cost is added to run the new factory. Five numbers come directly from the company's reported financial results. And, finally you enter the new tariff and tax rates.