Half-life and radioactive decay calculator

Calculate remaining quantity, elapsed time, half-life or initial quantity with exponential decay.

Calculate remaining quantity, elapsed time, half-life or initial quantity with exponential decay. Leave exactly one quantity blank when reverse solving is supported.

Initial quantity (N₀)

Half-life (T½)

Elapsed time (t)

Remaining quantity N(t)

Results

Initial quantity

Half-life

Elapsed time

Remaining quantity

Decayed quantity

Remaining percentage

Number of half-lives

Results

Calculation details