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How does radiocarbon dating help determine the age of archaeological remains?

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Svante Paabo stands smiling with one hand on a Neanderthal skeleton model in front of a blue Max Planck Institute for Evolutionary Anthropology banner. — Anthropology Max Planck Institute for Evolutionary Anthropology director Svante Pӓӓbo posing with a model of a Neanderthal skeleton.

Radiocarbon dating is a vital technique in archaeology used to determine the age of organic remains, typically those between 500 and 50,000 years old.12

The method relies on the carbon cycle. Living organisms constantly absorb carbon, including the radioactive isotope carbon-14, from the atmosphere through food or photosynthesis. When an organism dies, it stops taking in carbon, and the carbon-14 in its tissues begins to undergo radioactive decay at a constant, known rate, with a half-life of 5,730 ± 40 years.12

By measuring the remaining proportion of carbon-14 in a sample—often using an accelerator mass spectrometer—researchers can calculate how much time has elapsed since the organism's death. Because atmospheric carbon levels have fluctuated over time, raw dates are calibrated using data from sources like dendrochronology (tree-ring dating) to ensure accuracy. This process provides a reliable chronometric framework for understanding human history and the development of agriculture.234