Perhaps no job can add gray hairs and wrinkles like serving as President of the United States. While Presidents do live longer than their fellow citizens ("Even in the 19th century, when the average man died at age 47, U.S. Presidents lived an average of 69 years," according to Nancy Gibbs and Michael Duffy), their looks show the weight of the office famously quickly. But how fast? By using Microsoft's new age-guessing tool how-old.net, released Thursday, we might be able to get an idea. While Barack Obama's only been in office six years, judging by a photograph from 2009 and 2015, the wizards at Microsoft claim Obama's looks have aged 13 years. George W. Bush, according to these two images, added nine years to his face during his eight years working in the Oval Office. Bush's father, George H.W. Bush worked in the White House for four years--and his face grew four years older too. Bill Clinton and Ronald Reagan both served for 8 years. Clinton's features clocked 15 years while Reagan added a mere 2 years onto his looks during the same stretch.