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The Costs of the Manhattan Project

The U.S. Nuclear Weapons Cost Study Project was completed in August 1998 and resulted in the book Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons Since 1940 edited by Stephen I. Schwartz. These project pages should be considered historical.

– All figures in constant 1996 dollars –

Expenditures through August 1945:*

*Includes costs from 1940-42 for the National Defense Research Council and the Office of Scientific Research and Development. Excludes $76 million spent by the Army Air Forces on Project SILVERPLATE from September 1943 through September 1945 (Project SILVERPLATE covered the modification of 46 B-29 bombers in support of the Manhattan Project, trained the personnel of the 509th composite bombing group, and provided logistical support for units based at Tinian Island, launching point for the attacks on Japan).

$20 billion

Comparison With Selected WWII Expenditures:

(Source: Statistical Review?World War II: A Summary of ASF Statistics, Statistics Branch, Control Division, Headquarters, Army Service Forces, U.S. War Department, 1946, pp. 75-6. Cost data are for 1942-1945. The total cost to the United States for World War II was approximately $3.3 trillion.)

All bombs, mines and grenades — $31.5 billion

Small arms materiel (not incl. ammunition) — $24 billion

All tanks — $64 billion

Heavy field artillery — $4 billion

All other artillery — $33.6 billion

Atomic devices/bombs produced and date detonated:


Gadget July 16, 1945 Alamogordo
Little Boy August 6, 1945 Hiroshima
Fat Man August 9, 1945 Nagasaki
Bomb No. 4 unused

Average cost per atomic device/bomb:

$5 billion

Where Did The Money Go?

(estimated cumulative costs through December 31, 1945)


Site/Project Then-year Dollars Constant 1996 Dollars
OAK RIDGE (Total) $1,188,352,000 $13,565,662,000
K-25 Gaseous Diffusion Plant $512,166,000 $5,846,644,000
Y-12 Electromagnetic Plant $477,631,000 $5,452,409,000
Clinton Engineer Works, HQ and central utilities $155,951,000 $1,780,263,000
Clinton Laboratories $26,932,000 $307,443,000
S-50 Thermal Diffusion Plant $15,672,000 $178,904,000
HANFORD ENGINEER WORKS $390,124,000 $4,453,470,000
SPECIAL OPERATING MATERIALS $103,369,000 $1,180,011,000
LOS ALAMOS PROJECT $74,055,000 $845,377,000
RESEARCH AND DEVELOPMENT $69,681,000 $795,445,000
GOVERNMENT OVERHEAD $37,255,000 $425,285,000
HEAVY WATER PLANTS1 $26,768,000 $305,571,000
Grand Total $1,889,604,000 $21,570,821,000


Sources: Richard G. Hewlett and Oscar E. Anderson, Jr., The New World: A History of the United States Atomic Energy Commission, Volume 1, 1939/1946 (Oak Ridge, Tennessee: U.S. AEC Technical Information Center, 1972), pp. 723-724. Includes capital and operations costs from 1942 through 1945. Costs adjusted using a base year of 1944 (the year of highest Manhattan Project expenditures). Actual costs per facility per year are apparently unknown.

1Designed and constructed by E.B. Badger and Sons and the Consolidated Mining and Smelting Company of Canada in Trail, British Columbia and by E. I. duPont de Nemours and Company in Morgantown, West Virginia, Montgomery, Alabama, and Dana, Indiana.

Copyright © 2002 The Brookings Institution

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