The massive economic impact comes from the cost to Edinburgh Airport and airlines of losing all flights to and from the city for almost five days, as well as the effect on local businesses.
Emergency talks are now taking place on how to minimise any impact from future closures.
Schools in the city were expected to be hit by high levels of absences among both teachers and students as they return from the Easter holiday today.
Councillor Tom Buchanan, the city's economic development leader, was today planning to hold talks with Norfolkline, the operator of the Rosyth-Zeebrugge ferry route, about providing extra services to help get stranded passengers back.
He said: "We are very concerned about the effect this might have on business. It is costing the economy an absolute fortune.
"We are liaising with all partners and I will be asking if we can increase the number of ferries from Rosyth to continental Europe. We need to get people back to mainland Europe as soon as possible, as well as helping people get back to Edinburgh."
Edinburgh Chamber of Commerce estimated that the cost to Edinburgh Airport and city businesses would run into the hundreds of millions of pounds.
The chamber's deputy chief executive, Graham Birse, said: "There is no doubt that every day this goes on is costing businesses a substantial amount of money.
"There has been a significant inconvenience to everyone – leisure and business.
"There are people who are stranded overseas that should be at work or people who should be travelling to London on business who have needed to cancel their trips."
He added: "These events – which insurance companies would describe as acts of God – have costs and the cost is rapidly exacerbating. The cost, particularly for small businesses, is very significant indeed.
"There will be various empty offices and workplaces in Edinburgh now, where colleagues have not returned from Easter holidays."
Among those missing from their desks today was one of the city council's most senior members of staff. Dave Anderson, director of city development, had flown to San Francisco on a controversial visit to greet Edinburgh's entry in the round-the-world yacht race, and is struggling to make it back.
It is not known exactly what the impact will have been on schools, which reopened today following the Easter break and yesterday's local holiday. The city council has a list of on-call substitute staff that it hopes will be able to cover teacher absences.
The city's hospitality sector has been among those hit hard by the slump in visitors.
The Roxburghe Hotel, on Charlotte Square, has suffered a big rise in the number of cancellations since last week.
Marcello Ventisei, general manager at the Roxburghe, said: "What has been apparent is a much higher level of cancellations than normally be expected.
"There is a lot of uncertainty. There have been people cancelling because they think they might not be able to travel. The uncertainty is adding to the problem.
"Cancellations have not just been confined to individuals. Groups, conferences and events have also been exposed to that."
Taxi and private hire firms have also suffered a slump in trade. Kevin Woodburn, chairman of the Edinburgh Private Hire Association and a director of Edinburgh City Private Hire, said journeys to and from the airport usually represent about 10-15 per cent of his company's trade.
He said: "Since Thursday, any airport work has disappeared entirely. It has had a real impact on everybody's business."
Eddie Wood, who has worked at the airport for 20 years, said he had never suffered such a slump in trade.
Mr Wood, a driver's representative at Onward Travel, based at the airport, said his firm had lost almost all of its business.
But although he admitted that the firm was "struggling" as a result of the problems, he said passenger safety was more important than money.
"It has been very quiet since the cloud went up," he said. "We've never experienced anything like this.
"But it is wholly understandable that they don't want to take a chance because passenger safety is paramount.
"You just can't plan for something like this. We haven't budgeted for it – you can't – so we're struggling. We just have to hope the cloud moves."
But the chaos has not been bad news for everyone. Train companies have been running extra services, with ScotRail reporting business soaring and services fully booked.
And Edinburgh-based private jet firm Cloud9 said it has been "inundated" with enquiries from people trying to get home, including the Williams Formula 1 team, which is trying to get back from the Chinese Grand Prix.
Wedding left without key component .. the groom!
THOUSANDS have been caught up in the disruption to Edinburgh flights. Here are some of their stories:
The castle is booked, the dress has been bought and the rings are waiting to be exchanged, but Caroline Potter's wedding is missing one vital ingredient for Saturday's ceremony in Linlighgow: a groom. Since Thursday morning Andy Munro has been desperately trying to get a flight home from Denver, Colorado.
Caroline, from Abbeyhill, said: "It's frustrating because Andy almost made it out of Denver – he had been travelling by plane for four hours when they were forced to turn around."
Sarah Lee, from Marchmont, who owns a small PR business, has been stuck in Banff, Canada, since Saturday with her children, Joe, 14, and Katy, 19. Her sole employee has been manning the fort.
Kevin Wolbert, 20, from Duddingston, right, has shown his dedication to his position with Edinburgh Monarchs speedway racers by driving more than 1,000 miles from Germany to Armadale in 20 hours to get to an important competition.
Edinburgh South Green candidate Steve Burgess is still trying to go on his honeymoon. The Newington councillor married his Polish-born bride Julita on Saturday at Canongate Kirk. But her parents were unable to get to the wedding because their flight from Poland was cancelled. Lothians Green MSP Robin Harper stood in to walk Julita down the aisle.
Five employees due to be working at a specialist sports shop in the Capital remain stranded in America.
Staff at Run and Become, on Dalry Road, have been forced to recruit friends to help in the shop in their absence, while also closing earlier than usual. Among those stuck are manager Adrian Stott's wife and two daughters, all full-time workers at the busy shop.