Nuclear Blast Effects Calculator
This calculator estimates blast radii for nuclear detonations using cube-root scaling, a well-established physics principle. Enter the yield in kilotons to see approximate distances for various overpressure levels and their effects. This is for educational purposes only, helping understand the physics of blast scaling and the relationship between yield and destructive radius.
How We Calculate This
Blast radii use cube-root scaling: R(Y) = R₀ × (Y/Y₀)^(1/3), where R₀ are baseline radii at Y₀ = 1 kT. Baseline values are derived from weapons effects research. Fireball radius uses a separate scaling relationship.
Frequently Asked Questions
How does blast radius scale with yield?
Blast radius scales roughly with the cube root of yield. This means doubling the yield only increases the radius by about 26% (2^(1/3) ≈ 1.26). A 1000 kT weapon has only 10× the radius of a 1 kT weapon, not 1000×.
What do the overpressure numbers mean?
1 psi (6.9 kPa) breaks windows. 5 psi (35 kPa) collapses most residential buildings. 20 psi (140 kPa) destroys reinforced concrete structures. These are peak overpressures from the blast wave.
Is this calculator accurate?
The cube-root scaling law is physically sound for free-air bursts. Actual effects vary with burst height, terrain, weather, and building construction. This provides educational estimates, not precise predictions.
Why no fallout or radiation calculations?
Fallout depends heavily on burst type (air vs ground), weather, and terrain. Thermal radiation calculations would require additional inputs. This calculator focuses on blast overpressure only.
What was the Hiroshima bomb yield?
The Hiroshima bomb ("Little Boy") had a yield of approximately 15 kilotons. The Nagasaki bomb ("Fat Man") was about 21 kilotons. For comparison, modern strategic weapons range from hundreds to thousands of kilotons.
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You might also find these calculators helpful: Asteroid Impact Simulator, and Escape Velocity.
This calculator is for educational purposes only. It does not include targeting tools, fallout calculations, or maps. Effects are approximate and depend on many factors not modelled here.