Half-Life Calculator

Calculate any variable in the exponential decay equation N(t) = N₀ × (1/2)^(t/T½). Free online half-life calculator with step-by-step solutions for nuclear physics, radiometric dating, and pharmacology.

Input Values (enter any 3)leave one blank to solve

Initial Amount N₀

Remaining N(t)

Time t

Half-Life T½

💡 Defaults: N₀=100, N(t)=25, t=10 — solves for T½

ResultExponential Decay

Click "Calculate" to see the detailed steps.

Half-Life Calculator

This free online half-life calculator solves for any variable in the exponential decay equation $N(t) = N_0 \times (1/2)^{t/T_{1/2}}$. Enter any three values to find the fourth, with step-by-step solutions showing the decay constant $\lambda$ and the full decay function.

🔒 Client-side only⚡ Web Worker processing🌐 Works offline🛡️ Zero server logs