- More than $508 billion so far, according to the National Priorities Project.
- $1.3 trillion for total economic costs of Iraq war from 2002 to 2008, including interest costs of borrowing funds, lost investment, long-term veterans' health care and oil market disruptions, according to a November 2007 report from Congress' Joint Economic Committee.
- $100 billion to $200 billion, estimated in September 2002 by then-White House economic adviser Lawrence Lindsey. The White House openly contradicted him, saying that figure was far too high.
- $50 to 60 billion, estimated in late 2002 by then-White House budget director Mitch Daniels.
- $100 billion and three years to get "the country up and running again," projected in 2003 by L. Paul Bremer, then-chief of the U.S. occupation government in Iraq.
- Beyond 2008, between $1.7 trillion and $2.7 trillion - or more - by 2017 for the Iraq and Afghanistan wars, including long-term U.S. military occupation, estimate Nobel Prize-winning economist Joseph E. Stiglitz and Harvard University public finance expert Linda Bilmes.
- A cumulative cost of $1.2 trillion to $1.7 trillion for Iraq and Afghanistan wars by 2017, with Iraq generally accounting for three-quarters of the costs, according to the Congressional Budget Office.