How much Mark Zuckerberg has left after giving away 99% of his Facebook shares

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.

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.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.

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. 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.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 (£1.9 billion). At the time, Facebook said the cash would go on private jets needed for security reasons and to pay his tax bills.