AbraCalc

Carbon-14 Half-Life: 5730 Years

Carbon-14 has a half-life of 5730 years; after 11,460 years (two half-lives), 25% of the original amount remains.

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How to use this tool

  1. Enter initial amount, half-life (time units) and elapsed time (same units) in the fields above.
  2. Results update instantly as you type — or click Calculate.
  3. Read your remaining amount and the full breakdown beneath it.

Carbon-14 dating relies on its 5730-year half-life — calculate how much remains after any elapsed time.

Frequently asked questions

What substances have known half-lives?
Carbon-14 has a half-life of about 5,730 years (used in carbon dating). Uranium-238 has ~4.5 billion years. Iodine-131 used in medicine has ~8 days.
Can I use this for non-radioactive decay?
Yes — any process that halves on a fixed schedule (drug concentration, population loss, etc.) can be modelled this way.