Nuclear Weapon Effects Calculator

Input Weapon Yield
Yield (megatons)
Calculated Values
Ionizing radiation 500 REM = 5 Sievert
Air blast widespread destruction / fatalities = 5 psi
near-total destruction / fatalities = 20 psi
Fireball duration
Fireball minimum
airburst
surface burst
• These outputs are approximate, for ease of calculation, and your results may vary. All figures assume optimum burst height.
• Thermal radiation is non-ionizing electromagnetic radiation which has a significant heating effect. Third degree burns, cause tissue death all the way through the skin, are lethal unless treated by skin grafts.
• Ionizing radiation is electromagnetic radiation of sufficient frequency (and hence energy) to "knock off" electrons from atoms, thus ionizing them. In the 500 REM dosage range, mortality can run between 50% [450 rems] and 90% [600 rems] without heroic medical intervention.
• The 5 psi overpressure is sufficient to collapse most residential and light industrial structures. Injuries are universal, and fatalities are widespread. Exposed humans can actually survive such an overpressure, about 1/3 bar above standard, but injuries would result from debris. But the standard rule of thumb for estimating prompt fatalities from all causes [blast, thermal and radiation] is to count everyone inside the 5 psi blast overpressure contour around the hypocenter as a fatality.
• The 20psi overpressure is sufficient to severely damaged or demolish heavily built concrete buildings, and cause nearly 100% fatalities.
• Fireball duration is based on emission intensity reduction to 10% of peak.
• Fireball radius is based on a scaling law from "The Effects of Nuclear Weapons" (1977), Chapter IIc, Fireball radius scales with (Y^0.4), where Y is yield. A surface burst creates a larger fireball because some of the energy is reflected back up from the surface.
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