CHICAGO, Sept. 21 -- The money spent on one day of the Iraq war could buy homes for almost 6,500 families or health care for 423,529 children, or could outfit 1.27 million homes with renewable electricity, according to the American Friends Service Committee, which displayed those statistics on large banners in cities nationwide Thursday and Friday.

The war is costing $720 million a day or $500,000 a minute, according to the group's analysis of the work of Nobel Prize-winning economist Joseph E. Stiglitz and Harvard public finance lecturer Linda J. Bilmes.

The estimates made by the group, which opposes the conflict, include not only the immediate costs of war but also ongoing factors such as long-term health care for veterans, interest on debt and replacement of military hardware.

"The wounded are coming home, and many of them have severe brain and spinal injuries, which will require round-the-clock care for the rest of their lives," said Michael McConnell, Great Lakes regional director of the AFSC, a peace group affiliated with the Quaker church.

The $720 million figure breaks down into $280 million a day from Iraq war supplementary funding bills passed by Congress, plus $440 million daily in incurred, but unpaid, long-term costs.

But some supporters of the Bush administration's policy in Iraq say that even if the war is costly, that fact is essentially immaterial.

"Either you think the war in Iraq supports America's national security, or not," said Frederick W. Kagan, a resident scholar at the American Enterprise Institute. "If you think national security won't be harmed by withdrawing from Iraq, of course you would want to see that money spent elsewhere. I myself think that belief, on a certain level, is absurd, so the question of focusing on how much money we are spending there is irrelevant."

The war's unpaid long-term costs do not include "macro-economic consequences" described by Bilmes and Stiglitz, including higher oil prices, loss of trade because of anti-American sentiments and lost productivity of killed or injured U.S. soldiers.

In 2006, Bilmes, who was an assistant secretary of commerce under President Bill Clinton, and Stiglitz, a former chief economist at the World Bank, placed the total cost of the Iraq war at more than $2.2 trillion, not counting interest. The American Friends group used cost breakdowns and interest projections from the Congressional Budget Office to calculate the daily cost of war emblazoned on the banners flown in Boston, San Francisco, Philadelphia, Chicago and other cities.

The banners show what this could buy in terms of health care, Head Start programs, new elementary schools, free school lunches, renewable energy and hiring new teachers. Protest organizers say they hope to turn more people against the war by laying out its true financial impact.

"I think people are becoming more aware of these guns or butter questions," said Gary Gillespie, director of the group's Baltimore Urban Peace Program, which displayed the banners in the Baltimore suburb of Bel Air on Friday. "But when you talk about $720 million a day, even people who work on this issue are shocked by the number and shocked by what could have been done with that money. War has no return -- you're not producing a product."