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Radioactive Half-Life Calculator
N = N₀·(½)^(t/T½) — solve for remaining amount, elapsed time or the half-life itself.
Calculator
Results update as you type. Every step of the working is shown below.
Examples:
Result
Enter values above — the answer appears here instantly, with full working.
Formula used
N = N₀ · (1/2)^(t/T½)
Every result substitutes your values into this relation step by step above.
Assumptions
- First-order decay — constant probability per nucleus.
- Time and half-life must use the SAME unit.