How to use this calculator
Estimate the amount remaining after a decay interval. Enter starting amount, elapsed time (same units), half-life (same units). The result updates when you change an input. To compare two sets of inputs, save scenario A, then enter the second set; the result panel shows the difference.
Formula and limits
Remaining amount = initial amount × 2^(−elapsed time/half-life). Assumes a single exponential decay process. Not a medication dosing tool.
Worked example
The following example uses the calculator’s starting values. It is an illustration of the method, not a recommended target.
| Input | Example value |
|---|---|
| Starting amount | 100 |
| Elapsed time (same units) | 10 |
| Half-life (same units) | 5 |
Amount remaining in original units: 25
Interpreting your result
These are simplified mathematical models with explicit assumptions. Real populations and biological systems may not follow a constant exponential rate. No clinical dosing or treatment use is intended.
Comparing alternatives
Save the first result as scenario A, then change one input. The comparison shows the numeric difference; it does not label either result as better. Choose inputs that describe realistic alternatives. Values shown on screen are rounded, so calculations from rounded intermediate results may differ slightly.