About the Half-Life Calculator
Solves first-order decay problems for any missing variable.
What it is
Using N = N₀(½)^(t/t½), enter any three of initial amount, remaining amount, half-life, and elapsed time to solve for the fourth, with decay constant and mean lifetime shown alongside.
Features
Solve for any variable
N₀, N, t½, or t.
Isotope presets
~15-20 common isotopes auto-fill the known half-life.
Decay constant & mean lifetime
λ and τ computed from the half-life.
Decay curve chart
Plots the exponential curve with the solved point marked.