Carbon-14 Dating Calculator

Enter two of the three variables and press calculate to find the third.


A0 =

A(t) =

t =

Radiocarbon Dating

Radiocarbon dating (or simply carbon dating) is a radiometric dating technique that uses the decay of carbon-14 (14C) to estimate the age of organic materials, such as wood and leather, up to about 58,000 to 62,000 years Before Present (BP, present defined as CE 1950). Carbon dating was presented to the world by Willard Libby in 1949, for which he was awarded the Nobel Prize in Chemistry.

Since the introduction of carbon dating, the method has been used to date many items, including samples of the Dead Sea Scrolls, the Shroud of Turin, enough Egyptian artefacts to supply a chronology of Dynastic Egypt, and Ötzi the Iceman.

While a plant or animal is alive, it is exchanging carbon with its surroundings, so that the carbon it contains will have the same proportion of 14C as the biosphere. Once it dies, it ceases to acquire 14 C, but the 14 C that it contains will continue to decay, and so the proportion of radiocarbon in its remains will gradually reduce. Because 14 C decays at a known rate, the proportion of radiocarbon can be used to determine how long it has been since a given sample stopped exchanging carbon -- the older the sample, the less 14 C will be left.

Getting Started:

  1. Enter two of the three variables.
    A0 = the initial amount of Carbon-14, usually denoted in percentage with 100%
    A(t) = the final amount of Carbon-14
    t = the amount of time passed

  2. Press Calculate
    Your calculated values will be shown to the right of the text boxes and a graph
    will be displayed.