How much radiation can kill you?



please explain it in a scale that i can understand, also im asking because im doing research on nuka colas and seeing how much radiation it actually has.

In: Biology

This chart is probably the best explanation/comparison that I’ve ever seen :

To add, there is the minimum lethal dose that will kill by the action of the radiation itself, and higher doses kill more quickly. However, repeated smaller doses (smaller than the minimum lethal, but still very large) can also be deadly.

Lower doses can be deadly as well, causing (or significantly increasing the chances of) cancer or other major issues, and radiation burns in the lungs from inhaling ash can kill just by interfering with the lung function.

There’s no single answer to this. It depends on the type of radiation you were exposed to and how you were exposed to it (i.e., did you touch something contaminated, inhale contaminated dust…etc), the duration of the exposure, whether your whole body or just part of it was exposed, and a bunch of other factors. There are simply far too many variables to say unless you give us more info.

Someone already posted the xkcd image, so I’ll add another helpful article to it.


There’s a lot of helpful background information and factors that go into this. I don’t have time right now to explain all of the background info so I’ll answer the question as direct as possible.


There’s no set, single number that fits everyone since there are a huge number of factors that determine how radiation effects a person. However, the following is what most rad workers would use as an answer to “how much radiation would it take to kill someone” or in other words- what is the “Lethal Dose”. Information is found in the above provided link. Charts are on pages 5 and 6. Information on lethal dose is explained in pages 7 and 8 under the ARS Section. Note that the ranges and specific numbers can be different between countries and research groups. These are DOE Numbers.

The estimated lethal dose is labeled/measured as “**LD 50/30**”. This means that **50% of people** that receive the **LD,** **Lethal Dose** (measured in Rem or Sieverts) in a short amount of time to their whole body will die within **30 days.**

There are two LD 50/30 estimated ranges. The lower range is for those that don’t receive medical aid during the 30 days. The higher range is for those that do receive medical aid during the 30 days.

The LD 50/30 range without medical aid is **~350 Rem to ~450 Rem** acute whole body dose.The LD 50/30 range with medical aid is ~450 to ~900 Rem acute whole body dose. (Not super precise.

**ELI5** – If a person’s whole body is exposed to ~400 Rem of radiation in less than a day then there’s 50% chance that they’ll be dead in less than 30 days compared everyone else exposed to the same amount. This is without doctors or medical help. It’s hard to visualize how much a “Rem” of radiation is, but the xkcd chart helps a bit.

If a person receives medical aid then they have a better chance of surviving compared to without aid, or may survive higher amounts of radiation exposure. However, at this point it’s highly dependent on the person’s biology, aid provided, and other factors.

Also on the chart is acute ~1k-2k Rem for certain death with no medical care if that helps answer OP’s question.

EDIT: Spelling fixes.

EDIT 2: I realized I got tunnel-visioned into LD 50/30. Also on the chart is acute ~1k-2k Rem for certain death with no medical care.