No history yet
Half-Life Calculator
Solve for remaining quantity, initial quantity, time elapsed, or half-life in radioactive decay equations.
Half-Life Calculator
Calculate radioactive decay parameters.
Understanding the Half-Life Calculator
Our Half-Life Calculator helps you determine the rate of radioactive decay for any isotope. This physics and chemistry tool can solve for the remaining amount of a substance, its initial quantity, the time elapsed, or the specific half-life of the element.
How to use the Half-Life Calculator
- 1Select the variable you wish to solve for from the dropdown menu.
- 2Enter the known values for the other three parameters.
- 3Click 'Calculate' to see the result and a visual decay curve chart.
- 4The chart plots the amount of substance remaining over a period of five half-lives.
Common Use Cases
The Maths Behind the Calculation
Nt = N0 × (0.5)^(t / t½)The amount of substance remaining (Nt) is equal to the initial amount (N0) multiplied by one-half raised to the power of the elapsed time (t) divided by the half-life (t½).
Frequently Asked Questions
What is a half-life?
A half-life is the time required for one-half of the atoms of a radioactive substance to decay into another nuclear form.
Does half-life depend on the initial amount?
No, the half-life is a constant physical property of a radioactive isotope and does not depend on how much of the substance you start with.
Is radioactive decay linear?
No, radioactive decay is an exponential process. While the first half-life removes 50%, the second half-life removes 25% (half of what was left), and so on.
Regional Notice: United States
"Federal tax estimates are based on 2024 brackets. Consult a tax professional for official filing."