B61 vs W54 SADM
Nuclear weapon side-by-side comparison
B61
USA · 1968 · thermonuclear
340 kt
Variable yield tactical bomb.
W54 SADM
USA · 1961 · pure fission
1 kt
Special Atomic Demolition Munition.
Verdict
The B61 is 340× more powerful than the W54 SADM by yield. Both weapons are described in detail below, with side-by-side blast and thermal radii, casualty estimates at a reference urban density, and historical context.
Blast & thermal effects (air burst)
| Effect zone | B61 | W54 SADM |
|---|---|---|
| Yield | 340 kt | 1 kt |
| Fireball radius | 1.49 km | 0.14 km |
| Severe blast (20 PSI) | 3.30 km | 0.48 km |
| Moderate blast (5 PSI) | 7.05 km | 1.03 km |
| Light blast (1 PSI) | 20.06 km | 2.93 km |
| 3rd-degree thermal burns | 7.31 km | 0.67 km |
| 2nd-degree thermal burns | 13.09 km | 1.20 km |
Casualty estimate (dense urban target)
Estimated immediate fatalities if each weapon air-bursts over a city center with a population density of about 8,000 per km² (representative of dense urban cores like Manhattan or central Paris):
Real casualties depend strongly on time of day, sheltering, weather, and altitude of detonation. See the methodology page for the underlying formulas.
Hiroshima reference
The Hiroshima bomb (Little Boy) had a yield of approximately 15 kilotons. The B61 is 23× more powerful than the Hiroshima bomb. The W54 SADM is 15.0× smaller.
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FAQ
Is the B61 bigger than the W54 SADM?
Yes. The B61 (340 kt) is 340× more powerful than the W54 SADM (1 kt).
What is the blast radius of the B61 compared to the W54 SADM?
For an air burst, the B61 produces a 5 PSI moderate-blast radius of 7.05 km, versus 1.03 km for the W54 SADM. Severe blast (20 PSI): 3.30 km vs 0.48 km. 3rd-degree thermal burns: 7.31 km vs 0.67 km.
How many people would die from a B61 compared to a W54 SADM?
Detonated over a typical dense city center (8,000 people/km²), the B61 would cause an estimated 756,010 immediate fatalities. The W54 SADM would cause an estimated 16,135. Real numbers depend on time of day, sheltering, weather, and altitude of detonation.
How do the B61 and W54 SADM compare to the Hiroshima bomb?
The B61 is 23× more powerful than the Hiroshima bomb (Little Boy, 15 kt). The W54 SADM is 15.0× smaller than the Hiroshima bomb.