Question
What is half-life?
Half-life is the time it takes for an amount to drop to half of its current value.
Math
Use OmniCalc's half-life calculator to estimate how much remains after repeated halving over time.
Half-life calculator
Enter an initial amount, a half-life, and elapsed time to estimate the remaining amount, decay, and percent left.
Why this result matters
A distinct approved math/science utility that extends the growth-and-decay lane into exponential decay problems with broad classroom and practical relevance. Use the tool above to enter a few clear inputs and get a practical answer you can use right away.
This half-life calculator helps students and technical users estimate how much material remains after exponential decay. Enter an initial amount, a half-life, and elapsed time to see the remaining amount, how much decayed, and the percent left without doing the exponent math by hand.
Formula and method
The calculator uses exponential half-life decay: remaining amount = initial amount × (1/2)^(elapsed time / half-life).
Example
If the initial amount is 100, the half-life is 5, and the elapsed time is 15, the remaining amount is 12.5.
FAQ
Short answers to the questions people often ask before or after using the tool.
Question
Half-life is the time it takes for an amount to drop to half of its current value.
Question
Yes. The same repeated-halving idea is useful for medication clearance, signal decay, and other exponential decay problems.
Question
Exponential decay keeps halving the remaining amount, so it gets smaller and smaller without mathematically hitting zero in the formula.
Related calculators
If the next question is close to this one, these are the best pages to open next.
Math
Use OmniCalc's matrix calculator to analyze a 2×2 matrix and compute its determinant, trace, transpose, and inverse.
Math
Use OmniCalc's scientific calculator for powers, roots, logs, trig, and core arithmetic in one place.
Math
Use OmniCalc's log calculator to find logarithms for any positive number and valid base instantly.
Math
Use OmniCalc's exponent calculator to raise a base number to any chosen power instantly.