Despite wide-ranging concerns about getting older, most Americans want to live longer than the current average. But not too much longer. If it were up to them, Americans on average would like to live to be 87 years old -- nine years older than current life expectancy. But there's a limit: Just a quarter volunteer that they'd like to live to 100 or older. And even if medical breakthroughs made living to 120 possible, most would say no thanks.