Nuclear Physics

Half-Life Calculator

Calculate radioactive decay — find remaining quantity, elapsed time, or the number of half-lives.

Parameters

Initial quantity (N₀) (any unit: g, kg, atoms, etc.)

Half-life (t½)

Elapsed time (t)

Famous example: Carbon-14 has a half-life of 5,730 years

Results

N(t) = N₀ × (½)^(t/t½) · Decay constant λ = ln(2)/t½ · N(t) = N₀ × e^(−λt)

📐 Accuracy Note: Results are calculated using standard formulas and are provided for educational and reference purposes. While we strive for accuracy, floating-point arithmetic and rounding may introduce small errors. Do not rely on this tool for safety-critical, professional, or high-precision applications without independent verification.