Half-Life Calculator

Use the half-life decay formula to compute any one unknown when the other three values are known.

Half-life decay formula

The decay formula is N = N₀ × (1/2)^t/T, where N is the remaining amount, N₀ is the initial amount, t is elapsed time, and T is half-life.

Calculate

Initial amount (N₀)

Remaining amount (N)

Half-life (T)

Elapsed time (t)