In 1943, Allied forces began a long series of Pacific battles against the Japanese. Month after month, on islands like Tarawa, the Marshalls, the Marianas, Leyte, Iwo Jima, and Okinawa, the enemies fought with fierce determination. Surviving soldiers and civilians would describe horrifying bloodshed, and staggering numbers of people killed and wounded.

As American forces won territory ever nearer to Japan, military planners on both sides used casualty figures to construct their strategies. The Japanese intended to resist at all costs, deploying pilots as suicide missiles and expecting civilians to face invaders with sharpened bamboo sticks. Numerous Japanese citizens would be sacrificed, in this plan, to achieve better terms for peace.

On the U.S. side, President Harry Truman and his war advisers hotly discussed casualty estimates for a projected invasion. Congress and the public were solidly behind the war, but the president's advisers disagreed over the proposal's level of risk to human life, based on the number of Americans who had already been killed or wounded in the Pacific theater.


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.

Events are listed chronologically, with their casualties indicated in red. Cumulative numbers of casualties are indicated in gray.

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

Saipan (Jun-Jul 1944): 16,612 (Zeiler)
Leyte (Oct 1944): 15,584 (Zeiler)
Iwo Jima (Feb-Mar 1945): 26,821 (Zeiler)
Okinawa (Apr-Jun 1945): 49,151 (Zeiler)

Japanese Casualties

Saipan (Jun-Jul 1944): 23,811 (Zeiler)
Leyte (Oct 1944): 49,000+ (Zeiler)
Iwo Jima (Feb-Mar 1945): 22,000 (Zeiler)
Tokyo (Mar 9-10, 1945): 83,000 (Zeiler)
Okinawa (Apr-Jun 1945): 110,000 (Zeiler)
Hiroshima (Aug 6, 1945): 92,133 - 200,000 (Frank, Ienaga)
Nagasaki (Aug 9, 1945): 25,677 - 122,000 (Frank, Ienaga)

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.


My American Experience

My American Experience photos

Share Your Story

Were you there for the storming of Normandy beach? The Bombing of Germany? The Victory in the Pacific? Or perhaps your friends and relatives have passed on stories of their own World War II experiences that you would like to share.