Calculate the Amount of Radioactive Material Left


This page will calculate the amount of radioactive material left after a given length of time. Please enter the halflife, original amount, and elapsed time since the original amount was true and the current amount, and percent of the original will be returned. Please note that the time periods and mass amounts must be in the same units or the results will be inaccurate.
Halflife Amount Time

The amount remaining is: or percent of the original sample.
This page is written by Jonathan Tomshine, circa 1995.