Work out how much of a substance remains after a time, its decay constant, and how long until only 10% or 1% is left.
loading toolHow to use the half-life calculator
- Type your numbers in the boxes (pick your currency or units if asked).
- The answer updates as you type: no button to press.
- Copy the result, or share it on WhatsApp with one tap.
Questions
Is my data private?
Yes. Everything happens inside your own browser: nothing you type or choose is uploaded to us or anyone else.
Is it free?
Completely free, with no sign-up, no watermark and no limit on how many times you use it. Light ads keep the site running.
