The Costs of War

Introduction | The Costs of War | Sources

In the chaos of war, keeping track of personnel losses is a huge challenge. To find the numbers we present in The Costs of War, we collected data from over a dozen published sources.

We looked at what each source included. Some measured just the numbers of people killed, others counted the wounded, and others added the number of people missing. (All three are called "casualties.") Some tallies included only military personnel, others added Japanese civilian losses, and some made distinctions between combat and non-combat casualties.

For each battle or event, we assessed the range of numbers and what each one included, and chose the figure that was best defined and appeared closest to a consensus number. Since Thomas Zeiler's book provided data that approached consensus numbers for most of the Pacific battles, we chose to use his figures in most cases.

Casualty numbers for Hiroshima and Nagasaki vary widely. Some writers, like Richard Frank, count only the people reported as killed soon after the bombings, while others count the wounded and those who died days, weeks, months, or even years later, of radiation sickness or other afflictions. We chose to list a range for those two events, to acknowledge how hard it has been to count the number of human lives affected by the two bomb blasts.

-- The American Experience Online Team

U.S. Casualties

date	battle/event	figure	source	includes
June-July 1944	Saipan	16,612	Zeiler	killed, missing, and wounded
October 1944	Leyte	15,584	Zeiler	killed, missing, and wounded
February-March 1945	Iwo Jima	26,821	Zeiler	killed and wounded
April-June 1945	Okinawa	49,151	Zeiler	killed, missing, and wounded

Japanese Casualties

date	battle/event	figure	source	includes
June-July 1944	Saipan	23,811	Zeiler	killed
October 1944	Leyte	49,000+	Zeiler	killed
February-March 1945	Iwo Jima	22,000	Zeiler	killed
March 9-10, 1945	Tokyo	83,000	Zeiler	killed, many civilians
April-June 1945	Okinawa	110,000	Zeiler	killed
August 6, 1945	Hiroshima	92,133-200,000	Frank, Ienaga	killed, many civilians
August 9, 1945	Nagasaki	25,677-122,000	Frank, Ienaga	killed, many civilians

Source Citations

Frank, Richard B. Downfall: The End of the Imperial Japanese Empire. New York: Penguin Books, 1999.

Ienaga, Saburo. The Pacific War, 1931-1945: A Critical Perspective on Japan's Role in World War II. New York: Pantheon Books, 1978.

Zeiler, Thomas W. Unconditional Defeat: Japan, American, and the End of World War II. Wilmington, Delaware: Scholarly Resources Inc., 2004.