B83 vs Tsar Bomba
Nuclear weapon side-by-side comparison
B83
USA · 1983 · thermonuclear
1.2 Mt
Most powerful US weapon in active service.
Tsar Bomba
USSR · 1961 · thermonuclear
50 Mt
Largest nuclear weapon ever tested.
Verdict
The Tsar Bomba is 42× more powerful than the B83 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 | B83 | Tsar Bomba |
|---|---|---|
| Yield | 1.2 Mt | 50 Mt |
| Fireball radius | 2.47 km | 10.99 km |
| Severe blast (20 PSI) | 5.00 km | 17.13 km |
| Moderate blast (5 PSI) | 10.69 km | 36.60 km |
| Light blast (1 PSI) | 30.41 km | 104.12 km |
| 3rd-degree thermal burns | 12.26 km | 56.58 km |
| 2nd-degree thermal burns | 21.96 km | 101.33 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 B83 is 80× more powerful than the Hiroshima bomb. The Tsar Bomba is 3,333× more powerful.
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FAQ
Is the B83 bigger than the Tsar Bomba?
No. The Tsar Bomba (50 Mt) is 41.7× more powerful than the B83 (1.2 Mt).
What is the blast radius of the B83 compared to the Tsar Bomba?
For an air burst, the B83 produces a 5 PSI moderate-blast radius of 10.69 km, versus 36.60 km for the Tsar Bomba. Severe blast (20 PSI): 5.00 km vs 17.13 km. 3rd-degree thermal burns: 12.26 km vs 56.58 km.
How many people would die from a B83 compared to a Tsar Bomba?
Detonated over a typical dense city center (8,000 people/km²), the B83 would cause an estimated 1,737,845 immediate fatalities. The Tsar Bomba would cause an estimated 20,373,787. Real numbers depend on time of day, sheltering, weather, and altitude of detonation.
How do the B83 and Tsar Bomba compare to the Hiroshima bomb?
The B83 is 80× more powerful than the Hiroshima bomb (Little Boy, 15 kt). The Tsar Bomba is 3,333× more powerful than the Hiroshima bomb.