Half-Life Calculator

Name: Half-Life Calculator
Rating: 4.9 (1654 reviews)

Calculate radioactive decay and remaining quantity over time.

Calculator

Initial Quantity (any unit)

Half-Life (any time unit)

Time Elapsed (same unit as half-life)

Solve for

Result

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N(t) = N₀ × (½)^(t/t½). Carbon-14 half-life: 5,730 years (radiocarbon dating). Iodine-131: 8 days (medical imaging). Uranium-238: 4.5 billion years. Used in archaeology, medicine, and nuclear physics.