How I built a nuclear blast simulator from a 1977 public reference

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I wanted a nuke map that I could actually trust and that looked good on a phone, so I built one: Kaboomly , a free browser simulator that shows the effect rings of a nuclear detonation over any city on a 3D map. This post is about how the numbers are calculated, because that is the part people ask about most. The source: Glasstone & Dolan (1977) Almost every public blast calculator, including NUKEMAP, is built on the same book: The Effects of Nuclear Weapons by Samuel Glasstone and Philip J. Dolan, 3rd edition, 1977, published by the US Department of Defense and Department of Energy. It is public and has tables and scaling laws for blast, heat and fallout. For the code I ported the formulas from the open-source Python package glasstone (MIT license) to TypeScript and checked them against the tables in the book. Cube-root scaling The key idea is that blast distances scale with the cube root of the yield. If a 1 kiloton burst produces a given overpressure at distance d, a W kiloton burst produces the same overpressure at about d × W^(1/3). Ten times the yield only gives about 2.15 times the distance. Burst height uses the same law. Kaboomly takes the Hiroshima example (about 1,670 ft for roughly 12.5 kt) and scales it with the cube root of the yield, so every airburst is shown at a comparable height. The fireball is different: Glasstone & Dolan give it its own scaling of about W^0.4, so it grows a little faster than the blast rings. What the rings mean For a 15 kt airburst (the size of the Hiroshima bomb) the model gives roughly: 5 psi overpressure: about 1.6 km (1.0 mi) . Most residential buildings collapse. 1 psi overpressure: about 4.5 km (2.8 mi) . Windows shatter. Thermal radiation (third-degree burns) sits between the two. These are model estimates for ideal conditions. Real results depend on terrain, weather and building types, which is also why different simulators show slightly different numbers: they pick different burst heights, thresholds and airburst vs surface-burst defaults. Fallout Fallout is only drawn for surface bursts, using the idealized pattern from Table 9.93 in the book with a fixed 15 mph wind. It is a sketch of the shape, not a forecast. The map The front end is Astro plus MapLibre GL with OpenFreeMap tiles, so there is no map API key. Buildings come from the vector tiles and are colored ring by ring during a slow-motion replay. Population inside the rings comes from the GHSL 2020 grid, and the site only shows residents in an area, never casualty numbers. Try it You can pick any city or type your own address, choose a historical weapon from Little Boy (15 kt) to Tsar Bomba (50 Mt), and share a link to the result. The full method with references is on the how it works page . It is an educational tool. I hope it helps people understand the scale of these weapons, and why they should never be used.