Tsar Bomba

USSR · 1961 · 50 megatons · thermonuclear (hydrogen bomb)

Overview

Largest nuclear weapon ever tested.

With a yield of 50 megatons, the Tsar Bomba is 3,333× 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.

Tsar Bomba 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 zoneAir burstSurface burst
Fireball radius10.99 km8.79 km
Severe blast (20 PSI)17.13 km9.42 km
Moderate blast (5 PSI)36.60 km20.13 km
Light blast (1 PSI)104.12 km57.27 km
3rd-degree thermal burns56.58 km33.95 km
2nd-degree thermal burns101.33 km60.80 km
Lethal fallout zoneminimal~909.4 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 Tsar Bomba on a City

Use the interactive simulator to detonate the Tsar Bomba 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 Tsar Bomba

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FAQ

How big is the Tsar Bomba blast radius?

In an air burst, the Tsar Bomba produces a fireball roughly 10.99 km in radius and a 5 PSI moderate-blast zone of about 36.60 km — the area in which most residential buildings would collapse. The 1 PSI light-damage radius extends to roughly 104.12 km, where windows shatter.

What is the yield of the Tsar Bomba?

The Tsar Bomba has a yield of 50 megatons of TNT equivalent. That is 3,333× more powerful than the Hiroshima bomb.

Is the Tsar Bomba bigger than the Hiroshima bomb?

The Hiroshima bomb (Little Boy) had a yield of approximately 15 kilotons. The Tsar Bomba at 50 megatons is 3,333× more powerful than the Hiroshima bomb.

What thermal burn radius does the Tsar Bomba produce?

Thermal radiation from the Tsar Bomba can cause 3rd-degree burns out to roughly 56.58 km and 2nd-degree burns out to 101.33 km in an air burst. Surface bursts reduce these radii by approximately 40 percent due to ground absorption.

Sources: declassified DOE/DOD records, FAS, SIPRI, Glasstone & Dolan. See the full Weapons Database or learn about the scientific methodology.