Radiocarbon Dating Calculator
Determine the age of prehistoric organic samples by measuring the remaining carbon-14. Enter the percentage of C-14 remaining to calculate the age in years before present.
Percentage of original carbon-14 remaining in the sample
Default is 5730 years (Libby half-life). Some use 5568 years (Cambridge half-life).
How does radiocarbon dating work?
Radiocarbon dating measures the amount of carbon-14 remaining in an organic sample. Living organisms constantly exchange carbon with the atmosphere, maintaining a constant C-14 level. After death, C-14 decays at a known rate (half-life ≈ 5730 years). By measuring remaining C-14, we can calculate when the organism died.
What is the half-life of carbon-14?
The commonly used Libby half-life is 5730 years. Some older literature uses 5568 years (Cambridge half-life). The actual decay constant corresponds to 5730 ± 40 years. After one half-life, 50% of C-14 remains; after two half-lives, 25% remains, and so on.
What is the effective dating range for radiocarbon?
Radiocarbon dating is effective for samples up to about 50,000 years old (roughly 8-9 half-lives). Beyond this, the remaining C-14 is too small to measure accurately. Very recent samples (less than 100 years) may show elevated C-14 from nuclear testing (bomb pulse dating).
What materials can be radiocarbon dated?
Any organic material containing carbon can be dated: wood, charcoal, bone, shell, peat, soil organic matter, textiles, and ancient documents. Inorganic materials like stones or metals cannot be directly dated, but organic residues on them can be.