B61
USA · 1968 · 340 kilotons · thermonuclear (hydrogen bomb)
Overview
Variable yield tactical bomb.
With a yield of 340 kilotons, the B61 is 23× more powerful than the Hiroshima bomb. As a thermonuclear (hydrogen bomb) weapon, it derives its energy from a fission primary that ignites a much larger fusion secondary stage.
B61 Blast Effects
The table below shows the calculated radius of each effect zone for an air burst (optimal altitude, maximum blast spread) and a surface burst (ground level, with massive radioactive fallout). Formulas are scaling laws from The Effects of Nuclear Weapons (Glasstone & Dolan, 1977).
| Effect zone | Air burst | Surface burst |
|---|---|---|
| Fireball radius | 1.49 km | 1.19 km |
| Severe blast (20 PSI) | 3.30 km | 1.81 km |
| Moderate blast (5 PSI) | 7.05 km | 3.88 km |
| Light blast (1 PSI) | 20.06 km | 11.03 km |
| 3rd-degree thermal burns | 7.31 km | 4.39 km |
| 2nd-degree thermal burns | 13.09 km | 7.86 km |
| Lethal fallout zone | minimal | ~123.5 km |
All values are 1-D ground-distance estimates from the detonation point. Real-world effects depend on terrain, weather, and building construction.
Run the B61 on a City
Use the interactive simulator to detonate the B61 on any city worldwide. Click any location on the map to see the fireball, blast, and thermal radii overlaid on real geography with population-density-based casualty estimates.
🎯 Simulate B61Related Weapons
FAQ
How big is the B61 blast radius?
In an air burst, the B61 produces a fireball roughly 1.49 km in radius and a 5 PSI moderate-blast zone of about 7.05 km — the area in which most residential buildings would collapse. The 1 PSI light-damage radius extends to roughly 20.06 km, where windows shatter.
What is the yield of the B61?
The B61 has a yield of 340 kilotons of TNT equivalent. That is 23× more powerful than the Hiroshima bomb.
Is the B61 bigger than the Hiroshima bomb?
The Hiroshima bomb (Little Boy) had a yield of approximately 15 kilotons. The B61 at 340 kilotons is 23× more powerful than the Hiroshima bomb.
What thermal burn radius does the B61 produce?
Thermal radiation from the B61 can cause 3rd-degree burns out to roughly 7.31 km and 2nd-degree burns out to 13.09 km in an air burst. Surface bursts reduce these radii by approximately 40 percent due to ground absorption.