Updated

The average American could buy a house for the amount of money it takes to run Air Force One every hour.

The U.S. military has provided an updated estimate on that cost, first published by a taxpayer watchdog group and confirmed by FoxNews.com, and the number is staggering -- $181,757 per hour. That's the price tag for shuttling around President Obama, who, as it turns out, has spent more days abroad in his first two years than any other president.

Estimates over the years based on government reports and independent number-crunching have always reflected a steep cost for presidential travel, but the figure provided by the 89th Airlift Wing appears to be far higher than any previously reported. It was first published in a report this week on presidential travel by the National Taxpayers Union Foundation.

"It's astonishing. It's far higher than any other ... figure that's been reported on. It's very surprising, and of course it's just a fraction of the overall cost involved with presidential travel," said policy analyst Demian Brady, who wrote the study.

Master Sgt. Jeff Capenos, with the 89th Airlift Wing, told FoxNews.com the figure reflects operating costs ranging from fuel to engine and aircraft maintenance. Asked why other public estimates, which typically did not exceed $100,000, were so much lower, he said: "They were probably inaccurate."

The National Taxpayers Union referred to the publication of the statistic as a "major coup for public disclosure." Brady said the high price tag, as compared with prior estimates, could be attributed not just to inflation, but a better and more specific accounting of the associated costs, as well as upgrades made to the aircraft. He urged the administration to be even more forthcoming with presidential travel costs.

Brady also used his report in part to tackle rumors about the cost of Obama's 10-day post-election tour through Asia. One Indian newspaper report quoted an anonymous local official claiming it would cost U.S. taxpayers $200 million every day, a figure Brady dismissed as "wildly exaggerated." The Obama administration also shot down that figure, without detailing the actual cost.

But the trip to India, Indonesia, South Korea and Japan was by no means cheap. While a total by-the-day figure may be impossible to come by, Brady estimated that the 48 hours of flight time logged on the trip would cost at least $8.7 million for Air Force One alone. The president's latest visit to Lisbon, Portugal, for a NATO conference would add another $2.7 million, he figured.

That Lisbon trip also set a record for Obama. By Brady's accounting, Obama has now logged 55 days overseas, surpassing former President George H.W. Bush's record of 54 days during his first two years. In total, Obama has visited 26 countries -- some of them more than once -- over the course of 15 trips.

Having been in office only two years, Obama has not come anywhere close to the overall record for presidential travel. That was set by former President Bill Clinton over the course of his two terms in office. Clinton logged 233 days abroad over the course of 55 trips. Former President George W. Bush comes in at a close second, with 215 days abroad over the course of 49 trips.