Tsar Bomba vs Castle Bravo
Nuclear weapon side-by-side comparison
Tsar Bomba
USSR · 1961 · thermonuclear
50 Mt
Largest nuclear weapon ever tested.
Castle Bravo
USA · 1954 · thermonuclear
15 Mt
Most powerful US nuclear test.
Verdict
The Tsar Bomba is 3.3× more powerful than the Castle Bravo 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 | Tsar Bomba | Castle Bravo |
|---|---|---|
| Yield | 50 Mt | 15 Mt |
| Fireball radius | 10.99 km | 6.79 km |
| Severe blast (20 PSI) | 17.13 km | 11.51 km |
| Moderate blast (5 PSI) | 36.60 km | 24.60 km |
| Light blast (1 PSI) | 104.12 km | 69.98 km |
| 3rd-degree thermal burns | 56.58 km | 34.54 km |
| 2nd-degree thermal burns | 101.33 km | 61.86 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 Tsar Bomba is 3,333× more powerful than the Hiroshima bomb. The Castle Bravo is 1,000× more powerful.
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FAQ
Is the Tsar Bomba bigger than the Castle Bravo?
Yes. The Tsar Bomba (50 Mt) is 3.3× more powerful than the Castle Bravo (15 Mt).
What is the blast radius of the Tsar Bomba compared to the Castle Bravo?
For an air burst, the Tsar Bomba produces a 5 PSI moderate-blast radius of 36.60 km, versus 24.60 km for the Castle Bravo. Severe blast (20 PSI): 17.13 km vs 11.51 km. 3rd-degree thermal burns: 56.58 km vs 34.54 km.
How many people would die from a Tsar Bomba compared to a Castle Bravo?
Detonated over a typical dense city center (8,000 people/km²), the Tsar Bomba would cause an estimated 20,373,787 immediate fatalities. The Castle Bravo would cause an estimated 9,203,897. Real numbers depend on time of day, sheltering, weather, and altitude of detonation.
How do the Tsar Bomba and Castle Bravo compare to the Hiroshima bomb?
The Tsar Bomba is 3,333× more powerful than the Hiroshima bomb (Little Boy, 15 kt). The Castle Bravo is 1,000× more powerful than the Hiroshima bomb.