Half-Life Calculator
How to use the half-life calculator
- Choose what to calculate: the amount remaining, the starting amount, the time elapsed or the half-life.
- Type the other values. Use the same unit of time for the half-life and the time elapsed.
- The answer appears with the decay constant and the mean lifetime.
Frequently asked questions
What is the formula?
N = N₀ × (1/2)^(t / t½). After one half-life half is left, after two a quarter, and so on.