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Half Life Calculator


What does it mean by Half Life?

It is a concept used in nuclear science to help us get our heads wrapped around how the radioactive decay process plays out. If you take individual radioactive atoms, you will not know precisely when that particular atom will release its energy and "decay".

But when we have vast numbers of radioactive atoms together, we find statistical patterns in the length of time it takes for this large population to decay off. A concept called "half-life" was developed as one way of explaining this phenomenon and to help people in the nuclear sciences to perform calculations and work with this stuff.

How to find Half Life?

The time period associated with a half-life, let's say 7 days as an example, means that if you have a considerable number of radioactive atoms with that half-life, then after 7 days, half of them have released their excess energy and decayed into something else. So if we have 10,000 atoms of Exampelonium-111 with a half-life of 7 days, then after 7 days, we would only have 5,000 atoms of it. Then 7 days later, we'd only have 2,500 atoms, etc. A half life calculator helps you to find the exact time at which a radioactive element need to decay to its half.

Half Life Calculator "The half life of radioactive elements."

The half life calculator is a tool that helps you to understand and calculate the basics of radioactive decay. This calculator is based on half life formula of radioactive elements. One can use this tool to calculate the starting and the least amount of a substance or its decay constant. Half life equation and half life formula is described about radioactive elements to utilize this half life calculator in the best possible way.


Half Life Formula

Half life is based around the decay process and the number of unstable nuclei remaining after time "t." So the value of "t" can be found or determined using this equation

$$\text{N(t)} = \text{N\;(0)}\;*\;0.5/frac{t}{n}$$


  1. N(t) is the remaining quantity of a substance after time "t" has elapsed.
  2. N(0) is the initial quantity of this substance
  3. T is the half life

You can also determine the remaining quantity of a substance using some other parameters in the given formula like:

$$N(t) = N(0)\;*\;e^{(\frac{-t}{τ})}$$

$$N(t) = N(0)\;*\;e^{(-λt)}$$


  1. "τ" is the mean lifetime - the average amount of time a nucleus remains intact.
  2. "λ" is the decay constant (rate of decay).

Every one of the three parameters portraying a substance's radioactivity is connected in an accompanying manner:

$$T=\frac{ln(2)}{λ} = ln (2)*τ$$

What is Radioactivity? How does radioactivity works?

If you have ever wondered what Radioactivity is and could not find the answer then you have come to the right place. Radioactivity is a phenomenon that occurs in nature as well as in labs where it is done artificially. In this process, the nucleus of atoms disintegrates by emitting waves of energy called radiation.

The atoms of heavier elements do not have an ideal proton to neutron ratio. This makes them unstable. In order to approach the stable ratio, the atoms go through radioactive decay and in the process emit energy or various particles as by-products.

The most common types of materials showing radioactive decay are Uranium, Strontium, Plutonium and Radium. The reason for the instability in these and other radioactive materials is that they have extra neutrons in their atoms. This creates imbalance.

Types of Radioactive Decay based on Half Life

Radioactive decay is of three types,

  • Alpha decay
  • Beta decay
  • Gamma decay

Alpha decay is said to have occurred when the decaying atomic nucleus, emits an alpha particle as a by-product. An alpha particle is a helium nucleus. It has two neutrons and two protons. This means that the parent nucleus will have a mass for less than the original.

Alpha radiation is the most common kind of cluster decay. Alpha radiation is a property of relatively heavier atoms among the radioactive materials.

The alpha particles are the heaviest among all three types of radiation. Because of this, the velocity of propagation of these particles is shallow. Therefore, the probability of alpha particles
interacting with other particles is very high. This, in turn, makes the Alpha particles lose their energy very quickly and they quickly stop their forward motion within a few centimetres.

How to Calculate Half Life?

Calculating the half life of any substance is very easy by using this calculator. Our half life calculator outshines every other available calculator because of its easy to use nature and free of cost operation. You’ll need to follow the given steps to calculate the half life of any radioactive element you want without any hassle

  • Firstly, enter the initial or beginning amount of a substance in the first field
  • Secondly, enter the final amount of an element in the second field
  • Now enter the elapsed time (how long it took for that amount to the material to decay) in the third field
  • Now click on the "CALCULATE” Button

After putting all the values in the half life calculator, it will compute a result for you without any delaying. You can confirm the results by putting values manually in the half life formula.

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