W87
USA · 1986 · 300 kilotons · thermonuclear (hydrogen bomb)
Overview
Modern ICBM warhead.
With a yield of 300 kilotons, the W87 is 20× 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.
W87 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 | 1.42 km | 1.14 km |
| Severe blast (20 PSI) | 3.17 km | 1.74 km |
| Moderate blast (5 PSI) | 6.77 km | 3.72 km |
| Light blast (1 PSI) | 19.24 km | 10.58 km |
| 3rd-degree thermal burns | 6.95 km | 4.17 km |
| 2nd-degree thermal burns | 12.44 km | 7.46 km |
| Lethal fallout zone | minimal | ~117.5 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 W87 on a City
Use the interactive simulator to detonate the W87 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 W87Related Weapons
FAQ
How big is the W87 blast radius?
In an air burst, the W87 produces a fireball roughly 1.42 km in radius and a 5 PSI moderate-blast zone of about 6.77 km — the area in which most residential buildings would collapse. The 1 PSI light-damage radius extends to roughly 19.24 km, where windows shatter.
What is the yield of the W87?
The W87 has a yield of 300 kilotons of TNT equivalent. That is 20× more powerful than the Hiroshima bomb.
Is the W87 bigger than the Hiroshima bomb?
The Hiroshima bomb (Little Boy) had a yield of approximately 15 kilotons. The W87 at 300 kilotons is 20× more powerful than the Hiroshima bomb.
What thermal burn radius does the W87 produce?
Thermal radiation from the W87 can cause 3rd-degree burns out to roughly 6.95 km and 2nd-degree burns out to 12.44 km in an air burst. Surface bursts reduce these radii by approximately 40 percent due to ground absorption.