Half-Life Calculator

Accurately calculate radioactive decay, remaining quantity, and decay time for any substance with a known half-life value.

Decay Curve Visualization

Common Isotope Half-Lives

Isotope Half-Life Application
Carbon-14 (C-14) 5,730 years Radiocarbon dating
Uranium-238 (U-238) 4.47 billion years Geological dating
Potassium-40 (K-40) 1.25 billion years Archaeological dating
Cobalt-60 (Co-60) 5.27 years Medical radiotherapy
Iodine-131 (I-131) 8.02 days Thyroid treatment

Understanding Half-Life and Radioactive Decay

Half-life is a fundamental concept in nuclear physics and chemistry that describes the time required for half of the atoms in a radioactive substance to undergo decay. This natural process occurs in unstable atomic nuclei, which spontaneously emit radiation as they transform into more stable forms.

Our advanced half-life calculator allows you to accurately determine various aspects of radioactive decay, including the remaining quantity of a substance after a given time, the initial quantity based on final measurements, the half-life value itself, or the time elapsed based on quantity changes.

How to Use the Half-Life Calculator

Using our calculator is straightforward. Simply select the type of calculation you need to perform, enter the known values, and click "Calculate" to get instant results. The calculator works for any radioactive substance with a known half-life, from carbon-14 used in archaeological dating to medical isotopes like iodine-131.

The Half-Life Formula

The calculation is based on the exponential decay formula: N(t) = N₀ × (1/2)^(t / t₁/₂), where:

  • N(t) is the remaining quantity of the substance after time t
  • N₀ is the initial quantity of the substance
  • t is the time elapsed
  • t₁/₂ is the half-life of the substance

Applications of Half-Life Calculations

Half-life calculations have numerous practical applications across various fields:

  • Archaeology and Geology: Radiocarbon dating using carbon-14 to determine the age of artifacts and geological samples
  • Medicine: Calculating dosages and decay times for radioactive isotopes used in diagnosis and treatment
  • Nuclear Science: Managing nuclear waste and understanding nuclear reactions
  • Environmental Science: Tracking the decay of radioactive pollutants in the environment

Why Choose Our Half-Life Calculator?

Our calculator stands out with its user-friendly interface, accurate results, and versatile unit options. Whether you're a student, researcher, or professional in the field, our tool provides the precision you need for educational, scientific, or practical applications. The interactive decay curve visualization helps you better understand how the substance quantity decreases over time.

For more accurate results, ensure you use the correct half-life value for the specific isotope you're working with, as half-lives can vary from fractions of a second to billions of years depending on the substance.