MARK Zuckerberg has pledged to give away 99 per cent of his shares in Facebook, which at their current market valuation, is worth around $45 billion.
The giveaway will take place in Zuckerberg's lifetime. He's starting early - most billionaires, from Bill Gates to Warren Buffett, wait until their later years to start giving away their fortune.
Even if he were to give away the whole 99 per cent today, he could still sell the remaining 1 per cent for $450 million.
The value of that 1 per cent holding is expected grow. Shares in Facebook have climbed more than 180 per cent since their market value in 2012 and most analysts have a "buy" on the stock, meaning they expect further gains.
What about cash? Zuckerberg gets paid a $1 dollar a year basic salary, like other big tech CEOs. He'll get a few hundred thousand dollars a year more in company benefits.
He's also made some money cashing in Facebook shares.
When Facebook went public in 2012, Zuckerberg sold 30.2 million shares for a total of $1.13 billion.
Then in 2013, Zuckerberg cashed in some of his share options to the value of $3.3 billion. At the time, Facebook said the cash would go on private jets needed for security reasons and to pay his tax bills.
Then there's property.
Zuckerberg spent $10 million on a house in the Dolores Heights part of San Francisco.
Last year, he was rumoured to have spent $200 million or more on land in Kauai, the smallest of the Haiwaiian Islands.
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