What is BlastSim?

BlastSim is a free app for calculation of area affected by nuclear explosion based on formulae researched by Nuclear Explosion Archive. The software is intended for users who wish to know more about devastating effect of Nuclear explosion and maybe useful for evacuation planning. This app makes it easy to calculate affected area for just a few taps.

This app can be use to experiment with range of thermal radiation, radius of radio active fallout and possible number of casualties. It includes list of popular weapons in human history, such as Little boy, Fat man and Tsar Bomba.

It is also possible to input custom yield of the weapon (in kilotons)

List of formulae/reference papers used are on our website. Which can be access from the menu section in the app.

What’s New

Version 1.6.8

Update Framework version

Ratings and Reviews

4.7 out of 5
350 Ratings

350 Ratings

Owenmb14 ,

Oh the irony

Live in a suburb near NYC. wanted to see how safe/unsafe i was. After seeing the tsar bomba hit queens and im well in the screwed zone. An add to go to church shows up and get a chance for salvation comes up. 10/10

CF898 ,

Bugs, missing features

This app has some bugs that need to be fixed. The most glaring one is that the casualty counter often disappears, or is completely covered by an ad.

The app also uses some pretty user-hostile methods to display ads. There are often ads shown that take up the entirety of the screen, with no timer showing how long you have to look at them to continue using the app, nor is there any way to close the ads when they eventually expire other than simply waiting and hoping that they somehow go away on their own.

It also needs to be updated to optionally keep a cumulative sum of the casualties from multiple detonations.


Very surprised!!!

When I downloaded this app I thought it was going to be laggy and way to complicated but to my surprise this app is very good. It’s easy to use and gives you a good calculation of casualties, of course the casualties are to the blast because the app doesn’t take radiation into account. Although it would be very nice to have radiation poisoning taken into account. Overall this is a great app keep up the good work my dude.


Mapnitude Company Limited
32.1 MB

Requires iOS 11.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, French, German, Italian, Japanese, Korean, Portuguese, Russian, Simplified Chinese, Spanish, Thai, Traditional Chinese

Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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