It was revealed last month that Jamie Cooper-Hohn would receive a payout of £337m, before the details were known of the exact size of Sir Chris's fortune.
In Friday's detailed ruling, it emerged he had assets worth about £1bn.
US-born Mrs Cooper-Hohn, 49, had argued she was entitled to half their assets.
Sir Chris, 48, offered a quarter, arguing that he had made a special contribution to their wealth throughout their marriage.
Mrs Justice Roberts settled between the two arguments, accepting that Sir Chris was the "generating force" behind their financial success.
His "exceptional" business acumen and "financial genius" justified not splitting his assets equally, the judge said.
The sum is thought to be the biggest of its kind made by a judge in England. The couple separated following 17 years of marriage.
Sir Chris, the son of a car mechanic and a legal secretary, graduated from Southampton University before making his fortune as a hedge fund manager.
The couple set up the Children's Investment Fund Foundation, known as CIFF, which works to transform the lives of poor and vulnerable children in developing countries.
The pair, who have four children including triplets, have reportedly given away about £1bn.
This is not the first high-profile divorce case to result in a large payout.
The late Russian oligarch, Boris Berezovsky, featured in a multimillion-pound case three years ago when it was reported that his former wife Galina Besharova had agreed to accept between £165m and £220m as part of a settlement.
A judge has decided the American wife of London financier Sir Chris Hohn will get a third of his wealth - not half - in a further ruling on their High Court divorce case.