Half-Life Calculator
Calculate how much of a substance remains after a given time, based on its half-life.
Inputs explained
- Initial Amount — The starting quantity. Example: 100.
- Half-Life Period — The time it takes for half to decay. Example: 5 (years/hours/etc.).
- Elapsed Time — How much time has passed, in the same units. Example: 15.
How to use it
- Fill in the fields above — each input has a hint describing exactly what to enter
- Press Calculate to get your result instantly, right on this page
- Copy the result, save the tool to favorites, or share and embed it anywhere
Understanding the result
Example: 100 units with a 5-year half-life leaves 12.5 units after 15 years.
Frequently asked questions
Is the Half-Life Calculator free to use? Yes — it is completely free, with no sign-up, no download and no usage limits. You can use it as often as you need.
Is my data private? Yes. The calculation runs entirely in your browser — the values you enter are never sent to our servers, stored or shared with anyone.
What information do I need? Just the following: Initial Amount, Half-Life Period, Elapsed Time. Each field includes a hint explaining exactly what to enter.
Can I use it on my phone? Yes — the tool is fully responsive and works on any device, and the same calculator is available in the EasyWorkCalcs mobile app.
Privacy
Everything you enter into the Half-Life Calculator is processed entirely in your browser. Nothing is uploaded, stored or shared — your data stays on your device.