Mark Zuckerberg (© Noah Berger-Bloomberg via Getty Images)
Mark Zuckerberg's team of accountants has a big headache on its hands: The Facebook (FB) founder probably has a tax bill of around $1.1 billion.

Zuckerberg bought 60 million Facebook shares for just 6 cents each on May 18, 2012, the day of the company's initial public offering, CNNMoney reports. But even if he never sold those shares, they still count as income, bringing his income just from stock options last year to nearly $2.3 billion.

Under California's highest-tier tax bracket, Zuckerberg would likely get taxed at 48.3%. There are several loopholes the wealthy can take advantage of, but three California accountants that CNNMoney talked to estimated Zuckerberg's 2012 taxes at higher than $1 billion.

To put that in perspective, Zuckerberg is paying almost half of 1% of the total that all Americans paid in 2011, according to The Huffington Post.

Zuckerberg wasn't surprised by the tax bill. He sold some 30.2 million shares for $1.135 billion during the IPO just to cover the costs, according to CNNMoney.

Zuckerberg may be paying up, but his company has escaped the long arm of the IRS. My colleague Aimee Picchi reported in February that Facebook skipped out on federal and state income taxes and may have actually received tax refunds of $429 million.

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