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All years are Before Present (BP), meaning before AD 1950. Entries in the table represent seventy-five points on the IntCal20 curve that indicate relevant changes in the atmospheric 14C:12C ratio over some twenty thousand years. Points may be compared with fluctuations in the Marine Isotope Stage (MIS) record [chart].
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Enter any date from 2944 to 21155 14C years (no commas)
There is also a download available as a zip file [download].
The presentational format of the table and calculator output might tend to appear more precise than the reality of the situation as regards putting an age to something. A margin of uncertainty is advised, typically ±200 years in the case of the above conversions based on the IntCal20 curve.
Whilst every care is taken, no liability is assumed.
IntCal20 data (9,501 entries)
Prepared by Brian Williams, June and December 2023.