Harvard Business School graduates earn an average of US$3.6m over a 20 year, post-graduation time period, according to a new MBA salary survey.MBA Salaries for Graduates of Top US Business SchoolsOther business school alumni that attended top ranked MBA programs in the US enjoyed similar accumulated salaries over the past 20 years. MBA alumni from the Wharton School, Stanford University, Columbia Business School, Tuck School of Business, MIT: Sloan, and Kellogg School of Management all witnessed average salaries of above US$3m, combined over a 20 year period.Other US MBA Salary DataOn average, MBA alumni from the 57 US business schools in Businessweek\u0027s 2010 MBA ranking saw salaries totaling US$2.4m over the course of a 20 year career. This equates to a US$120,000 annual MBA salary, though it should be noted that alumni tend to earn higher annual salaries as their careers mature, so fresh graduates should expect less initially.The MBA pay scaleThe rising pay scale of MBA alumni is portrayed in the results shown for the top 10 business schools in Businessweek\u0027s salary ranking. After a 10 year career, average MBA salaries at the top 10 schools were found to be US$132,000 per annum. After a 20 year career, this figure increases to US$190,800 per annum.Unsurprisingly, the MBA salary difference between top ranked US business schools, and those that are usually found lower down the list on MBA rankings was significant.As reported by Businessweek, while the MBA salaries of the alumni from the top 10 business schools averaged out at over US$3m each during the 20 year period, alumni from the remaining 47 schools in the US publication\u0027s ranking reported average salaries of under US$2.3m.This table shows the Businessweek MBA salary data of the top 10 rated business schools in the QS Global 200 Top Business School Report regional rating for North America. Survey MethodologyConducted for Bloomberg Businessweek, the MBA salary data was collected by Payscale through information submitted by individuals on various online wage comparison tools. While base salaries and bonuses were included, stock and options, which are often offered to high level executives as part of their remuneration packages, were excluded.