Nuclear blast map
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Detonations
Place
34.3955, 132.4549
Weapon
Burst height
Enter the height yourself. Above 30 km counts as high altitude, where the effect is EMP.
Fallout
Drives the fallout. Atomic bombs are 100 %; thermonuclear weapons are often taken as 50 %.
Wind
Visibility and ground
Your own rings
Leave empty to draw no ring.
Time
Units
Effect zones
Fireball0.1 mi
The fireball at its largest. If it touches the ground, almost everything inside is destroyed and fallout increases. Area: 0.03 mi².
Heavy damage (20 psi)0.34 mi
Reinforced concrete buildings are severely damaged or demolished. Survival here is very unlikely. Area: 0.36 mi².
Initial radiation (500 rem)0.71 mi
A dose that can kill more than half of those exposed without medical care. Thick walls and earth reduce it. Area: 1.6 mi².
Moderate damage (5 psi)0.98 mi
Most homes collapse; injuries and deaths are widespread. Fires break out. Area: 3.02 mi².
Third-degree burns1.44 mi
Deep burns to exposed skin. Life-threatening over large areas. Area: 6.52 mi².
Second-degree burns1.78 mi
Blistering burns. Shade or being indoors protects. Area: 9.91 mi².
Dry materials ignite1.96 mi
Newspaper, dry leaves and similar materials can catch fire; fires start. Area: 12.1 mi².
First-degree burns2.27 mi
Redness like a sunburn. Area: 16.2 mi².
Light damage (1 psi)2.82 mi
Windows shatter. Flying glass and debris cause injuries; staying away from windows saves lives. Area: 25 mi².
Fallout (one hour after)
The fireball does not touch the ground, so no significant local fallout is expected.
Mushroom cloud
Top height
4.19 mi
Width (radius)
0.91 mi
What happens when?
Approximate values; terrain, buildings and weather change the real outcome.
Watch the explosion
Press Detonate to watch the flash and the blast wave second by second, the fallout hour by hour, and the dose rate falling over the years. You can also drag the timeline yourself.
Tap anywhere on the map: overpressure, heat, radiation and fallout at that point show up here.
How to use it
Pick a place and set the weapon's yield and burst height. The tool draws how far the blast wave, heat, radiation, fallout and EMP reach, and shows what happens at any point you tap and the dose you would receive in a shelter. The calculations follow Glasstone and Dolan's The Effects of Nuclear Weapons.
- 1
Pick a place
Drag the marker on the map, search for a city or use your location.
- 2
Set the weapon
Choose a preset or enter the yield and burst height yourself.
- 3
Detonate and watch
Watch the flash and the blast wave second by second and the fallout hour by hour. Tap a point to see what happens there.
How to protect yourself from a nuclear explosion
- 1
Do not look at the flash; lie down at once.
The moment you see the explosion, lie face down and cover your head and exposed skin. The blast wave arrives after the light, and the farther you are from ground zero, the longer it takes.
- 2
Once the blast has passed, get into the nearest solid building.
Stay away from windows. Ready.gov says you will have 10 minutes or more to find a shelter before fallout arrives. Buildings with brick or concrete walls, basements, underground car parks and the centre of large buildings give the best protection.
- 3
Stay inside.
Unless officials say otherwise, spend the first 24 hours in the most protected part of the building. Close windows and doors, and turn off fans, air conditioners and forced-air heating. The fallout dose rate drops quickly: according to Glasstone and Dolan, every sevenfold increase in time after the explosion cuts the dose rate to about a tenth.
- 4
Get the dust off you.
Once inside, take off your outer clothing without shaking it and put it in a bag; Ready.gov says this can remove up to 90% of radioactive material. Shower, or wash with soap and water. Hand sanitiser does not protect against radioactive material. Food kept indoors is safe; do not eat uncovered food left outside or produce from your garden until officials say it is safe.
- 5
Follow official announcements.
A battery-powered or hand-crank radio keeps you informed when power and internet are down. In an emergency call your local emergency number (112 in Türkiye and across Europe).
Source: Ready.gov, Nuclear Explosion
How it is calculated
Blast wave.
Calculated with the Defense Nuclear Agency's (DNA) 1 kiloton standard blast relations, scaled with the cube-root rule and corrected for the burst height. The results were compared with H. L. Brode's (1986) approximations. The "Air burst" option finds the height that carries your chosen overpressure the farthest.
Heat and burns.
Thermal radiation comes from the visibility-dependent curves of the Soviet source Iadernoe oruzhie (1987). Burn thresholds are for exposed, medium-toned skin and vary with yield, following Glasstone and Dolan. The ignition threshold for dry materials is the book's value for newspaper.
Initial radiation.
The gamma and neutron dose of the first minute comes from the curves of the same Soviet source. 500 rem is a dose that can kill more than half of those exposed without medical care (Waselenko et al., 2004).
Fallout.
Local fallout, which forms when the fireball touches the ground, is drawn with Glasstone and Dolan's idealized dose-rate contours (Table 9.93): the dose rate one hour after the burst depends on the fission share, the wind speed and the terrain. The dose rate falls as t⁻¹·². The dose received in a shelter uses the book's transmission factors (Table 9.120). Real fallout can take a very different shape depending on high-altitude winds, rain and terrain.
Fireball, cloud, crater and EMP.
From Glasstone and Dolan's formulas and charts. The EMP zone is the area visible from the burst point up to the horizon, for bursts above 30 kilometres, which the book counts as high altitude; the strength of the pulse is not calculated.
Wind and map.
The "Current wind at this point" button fetches the surface wind from the Norwegian Meteorological Institute (MET Norway). Map tiles come from OpenFreeMap, map data from OpenStreetMap contributors.
The digitized heat and radiation curves come from the open-source glasstone library (MIT licence, © 2016 GOFAI). The results were compared with the book's worked examples. All values assume flat ground and a standard sea-level atmosphere; buildings, hills and weather change the real outcome.
Frequently asked questions
How do I use the nuclear blast map?
Drag the ground zero marker on the map or press My location. Choose a preset or enter the yield and height yourself. The rings show the effect zones; tap any point on the map to see the overpressure, heat, radiation and fallout there. The Copy link button lets you share your settings as a link.
How accurate are the calculations?
The values are approximate. The formulas assume flat ground, clear air and sea level; buildings, hills, humidity and wind change the real outcome. The methods and sources are listed in the How it is calculated section of this page. The tool is meant for learning and preparedness and does not replace an official risk assessment.
Why is there sometimes no fallout?
Local fallout forms when the fireball touches the ground and soil and debris are drawn into the cloud. Air bursts whose fireball stays off the ground produce no significant local fallout; the Hiroshima and Nagasaki explosions were air bursts too. To see fallout, choose Surface for the burst height.
What should I do if a nuclear explosion happens?
If you see the flash, lie down and cover your head. Once the blast wave has passed, get into the nearest solid building, stay away from windows and stay inside for at least 24 hours unless officials say otherwise. The protective steps on this page give the details.
How much does a basement or an apartment protect from fallout?
According to Glasstone and Dolan's transmission factors, a basement lets through about 5 to 10 percent of the outdoor dose. The upper floors of a multistorey apartment building bring this down to about 1 percent, and a shelter under roughly a metre of earth to between 0.1 and 0.5 percent. Tap a point on the map and choose where you are and how long you stay to compare the doses.
Why does the map not show deaths and injuries?
Such estimates depend heavily on the time of day, the way buildings are built and where people are at that moment. A rough number would be misleading, so the map does not estimate casualties; it shows the effect zones and how to protect yourself.
Is my location or the places I pick stored?
No. All calculations run on your device. Map tiles load from OpenFreeMap. If you ask for the current wind, the rounded coordinates of the point are sent to MET Norway through our server. The settings in a shared link sit after the # sign of the address and never reach the server. Details are on our privacy page (in Turkish).
What is EMP, and why is it so large on the map?
EMP is the electromagnetic pulse of a nuclear weapon exploding very high up. For bursts above 30 kilometres the pulse can reach the whole area visible from the burst point up to the horizon, so the ring spans hundreds of kilometres. It can damage electronics and the power grid, but the map does not calculate the strength of the pulse.