Here are the relevant links for this story:

The Watson Institute of Brown University Report

Business Insider Built An Excellent 1-Page Slideshow From The Report

And a summary from Yahoo:

Yahoo

A report out of Brown University estimates that the U.S. wars in Afghanistan and Iraq--together with the counterinsurgency efforts in Pakistan--will, all told, cost $4 trillion and leave 225,000 dead, both civilians and soldiers.

The group of economists, anthropologists, lawyers, humanitarian personnel, and political scientists involved in the project estimated that the cost of caring for the veterans injured in the wars will reach $1 trillion in 30 or 40 years. In estimating the $4 trillion total, they did not take into account the $5.3 billion in reconstruction spending the government has promised Afghanistan, state and local contributions to veteran care, interest payments on war debt, or the costs of Medicare for veterans when they reach 65.

The Congressional Budget Office, meanwhile, has assessed the federal price tag for the wars at $1.8 trillion through 2021. The report says that is a gross underestimate, predicting that the government has already paid $2.3 trillion to $2.7 trillion.

More than 6,000 U.S. troops and 2,300 contractors have died since the wars began after Sept. 11. A staggering 550,000 disability claims have been filed with the VA as of 2010. Meanwhile, 137,000 civilians in Afghanistan and Iraq have died in the conflict. (Injuries among U.S. contractors have also not yet been made public, further complicating the calculations of cost.) Nearly 8 million people have been displaced.