FORTUNE — You would have to combine the wages of more than 400 CVS Caremark employees to match the salary of the company’s CEO, Larry Merlo.

CVS CVS has the greatest disparity between CEO pay and the median wage of its employees among the 100 highest-grossing companies in the U.S., according to a study released Thursday by compensation research company PayScale, Inc. Merlo’s $12.1 million salary is 422 times the size of the median wage for CVS employees: $28,700.

PayScale conducted a survey to find the median pay for workers at the 100 companies and determined the CEO-to-worker pay ratio in each case. Other companies with massive disparities include Goodyear Tire & Rubber GT , which comes in second with a ratio of 323 to 1, thanks to CEO Richard Kramer’s $15 million salary versus the median wage of $46,700 for the company’s workers. Walt Disney DIS CEO Robert Iger makes more than $17 million, which compares with a $60,300 median wage for his company’s employees – making for a ratio of 283 to 1.

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As economic inequality and the inefficiency of capitalism dominate recent news, PayScale’s data highlights the pay gaps between CEOs and typical employees at their company,” Katie Bardaro, lead PayScale economist, said in a statement. “Except for the few CEOs who take home almost no cash compensation, the average CEO-to-worker pay ratio for the 100 companies examined is 86 to 1.”

Because their CEOs take only $1 each in annual compensation, both Google GOOG and Sears SHLD had ratios of 0 to 1. PayScale says employees of retailer Kohl’s have the lowest typical median wage, at $28,500, while Google employees have the highest at $115,900.

The report’s release coincides with a massive movement among the world’s fast-food workers, many of whom went on strike on Thursday in a coordinated effort to earn a wage increase to $15 per hour. The striking workers – who said protests were planned in 150 cities and several countries across the globe – are also seeking the right to form a union.

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Meanwhile, the compensation of the executives at restaurant chain Chipotle Mexican Grill CMG was deemed high enough by a healthy majority of the company’s shareholders. More than three-quarters of Chipotle shareholders nixed an executive pay plan that last year gave co-CEOs Steve Ells and Montgomery Moran almost $50 million in combined compensation.