Carbon Dating Calculator
Calculate the age of organic materials using carbon-14 dating based on remaining C14 percentage. Free online radiocarbon dating calculator with decay curves and detailed breakdowns.
About This Calculator
What is Carbon Dating?
Carbon dating (also known as radiocarbon dating or carbon-14 dating) is a scientific technique used to determine the age of organic materials. Developed by Willard F. Libby in the 1940s, it relies on measuring the amount of radioactive carbon-14 remaining in a sample and comparing it to the known decay rate. All plants and animals absorb carbon-14 from the atmosphere throughout their lives. When they die, they stop absorbing C14, and the existing C14 begins to decay at a predictable rate with a half-life of 5,730 years.
How the Calculation Works
The calculator uses the radioactive decay formula: age = (T½ / ln(2)) × ln(100 / C14%), where T½ = 5,730 years (the half-life of carbon-14). Enter the percentage of C14 remaining in your sample, and the calculator instantly computes the estimated age in years along with the number of half-lives that have elapsed. The decay curve chart visualizes the exponential decrease of C14 over a 60,000-year timespan.
Regional Notes
Carbon dating is a universal scientific method used worldwide for archaeology, paleontology, geology, and anthropology. Leading laboratories include the Oxford Radiocarbon Accelerator Unit (UK), the NSF Arizona AMS Laboratory (US), and the Radiocarbon Laboratory at the Birbal Sahni Institute of Palaeosciences (India). Modern calibration curves (IntCal20) incorporate tree-ring data from Europe, North America, and the Southern Hemisphere to improve accuracy for all regions.
Frequently Asked Questions
How does carbon dating work?
Carbon-14 decays with a 5730-year half-life. The age of a sample is calculated using the formula: age = (half-life / ln(2)) × ln(100 / remaining C14%). Living organisms have 100% C14 at death, and the percentage decreases exponentially over time.
What is the half-life of carbon-14?
The half-life of carbon-14 is 5730 years (±40 years). After 5730 years, half of the original C14 remains. After 11,460 years, 25% remains. After 17,190 years, 12.5% remains.
How far back can carbon dating go?
Carbon dating can reliably date samples up to ~50,000–60,000 years old (about 9–10 half-lives). Beyond that, too little carbon-14 remains for accurate measurement with current technology.
What materials can be carbon dated?
Only organic materials can be carbon dated: wood, charcoal, bone, shell, leather, peat, pollen, fabric, paper, and other carbon-based remains. Inorganic materials like stone, metal, and pottery cannot be directly dated using radiocarbon.
What affects the accuracy of carbon dating?
Atmospheric C14 levels vary over time due to solar activity, volcanic eruptions, and fossil fuel emissions. Calibration curves (like IntCal20) correct for these variations. Contamination from modern carbon sources can also affect results. AMS (Accelerator Mass Spectrometry) requires only milligram-sized samples.
Who discovered carbon dating?
Carbon dating was developed in the 1940s by Professor Willard F. Libby at the University of Chicago. He was awarded the Nobel Prize in Chemistry in 1960 for this discovery.
What is the difference between C12, C13, and C14?
Carbon-12 (98.9% of natural carbon) and carbon-13 (1.1%) are stable isotopes. Carbon-14 is radioactive and makes up about 1 part per trillion of atmospheric carbon. C14 is constantly produced in the upper atmosphere when cosmic rays hit nitrogen atoms.
Can carbon dating be used on fossils?
Carbon dating is limited to samples up to ~60,000 years old. Dinosaur fossils are millions of years old, so they contain no detectable C14. Older fossils are dated using other radiometric methods like potassium-argon or uranium-lead dating.