W87
USA · 1986 · 300 kilotons · thermonuclear (hydrogen bomb)
Overview
Modern ICBM warhead.
With a yield of 300 kilotons[1], the W87 is 20× more powerful than the Hiroshima bomb. As a thermonuclear (hydrogen bomb) weapon, it derives its energy from a fission explosion that ignites fusion fuel, releasing on average roughly equal energy from fission and fusion. [2]
W87 Blast Effects
The table below shows the calculated radius of each effect zone for an air burst at optimum height. Values are scaling laws from The Effects of Nuclear Weapons (Glasstone & Dolan, 1977) and the published effects scaling table[3, 4].
| Effect zone | Radius (air burst) |
|---|---|
| Fireball radius | 0.60 km |
| Severe blast (20 psi) | 1.57 km |
| Moderate blast (5 psi) | 4.16 km |
| Light blast (1 psi) | 11.4 km |
| 3rd-degree thermal burns | 7.40 km |
| 2nd-degree thermal burns | 9.32 km |
| 1st-degree thermal burns | 11.9 km |
All radii assume an air burst at optimum height and are 1-D ground-distance estimates from the detonation point. Real-world effects depend on terrain, weather, and building construction. Casualty and fallout estimates are not shown pending a verified population and fallout model.
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 (air burst at optimum height) overlaid on real geography.
🎯 Simulate W87Related Weapons
FAQ
How big is the W87 blast radius?
In an air burst at optimum height, the W87 produces a fireball roughly 0.60 km in radius and a 5 psi moderate-blast zone of about 4.16 km — the area in which most residential buildings would collapse. The 1 psi light-damage radius extends to roughly 11.4 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.[5]
What thermal burn radius does the W87 produce?
In an air burst at optimum height, thermal radiation from the W87 can cause 3rd-degree burns out to roughly 7.40 km, 2nd-degree burns to 9.32 km, and 1st-degree burns to 11.9 km.
Sources
- 1.Source: Nuclear Weapon Archive (Carey Sublette), Complete List of All U.S. Nuclear Weapons (last changed 30 Mar 2023) — retrieved Oct 2026
- 2.Source: US DoD & ERDA (Glasstone & Dolan), via Atomic Archive, The Effects of Nuclear Weapons, 3rd ed. (1977), Chapter 1 — retrieved Oct 2026
- 3.Source: U.S. DoD / DOE (Glasstone & Dolan, via Atomic Archive), The Effects of Nuclear Weapons, 3rd ed. (1977) §2.127 — retrieved Oct 2026
- 4.Source: Wikipedia, Effects of nuclear explosions — scaling-law table — retrieved Oct 2026
- 5.Source: US DOE / NNSA Nevada Field Office, United States Nuclear Tests, July 1945 through September 1992 (DOE/NV-209 Rev. 16, Sep 2015), NNSS publication library — retrieved Oct 2026