Trinity vs Joe-1 (RDS-1)
Nuclear weapon side-by-side comparison
Trinity
USA · 1945 · pure fission
25 kt
First nuclear test.
Joe-1 (RDS-1)
USSR · 1949 · pure fission
22 kt
First Soviet nuclear test.
Verdict
The Trinity is 1.1× more powerful than the Joe-1 (RDS-1) 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 | Trinity | Joe-1 (RDS-1) |
|---|---|---|
| Yield | 25 kt | 22 kt |
| Fireball radius | 0.53 km | 0.50 km |
| Severe blast (20 PSI) | 1.39 km | 1.34 km |
| Moderate blast (5 PSI) | 2.98 km | 2.86 km |
| Light blast (1 PSI) | 8.48 km | 8.13 km |
| 3rd-degree thermal burns | 2.51 km | 2.38 km |
| 2nd-degree thermal burns | 4.49 km | 4.26 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 Trinity is 2× more powerful than the Hiroshima bomb. The Joe-1 (RDS-1) is 1× more powerful.
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FAQ
Is the Trinity bigger than the Joe-1 (RDS-1)?
Yes. The Trinity (25 kt) is 1.1× more powerful than the Joe-1 (RDS-1) (22 kt).
What is the blast radius of the Trinity compared to the Joe-1 (RDS-1)?
For an air burst, the Trinity produces a 5 PSI moderate-blast radius of 2.98 km, versus 2.86 km for the Joe-1 (RDS-1). Severe blast (20 PSI): 1.39 km vs 1.34 km. 3rd-degree thermal burns: 2.51 km vs 2.38 km.
How many people would die from a Trinity compared to a Joe-1 (RDS-1)?
Detonated over a typical dense city center (8,000 people/km²), the Trinity would cause an estimated 135,018 immediate fatalities. The Joe-1 (RDS-1) would cause an estimated 124,095. Real numbers depend on time of day, sheltering, weather, and altitude of detonation.
How do the Trinity and Joe-1 (RDS-1) compare to the Hiroshima bomb?
The Trinity is 2× more powerful than the Hiroshima bomb (Little Boy, 15 kt). The Joe-1 (RDS-1) is 1× more powerful than the Hiroshima bomb.