Use this geological calculation for a transparent first-pass interpretation of measured rock, soil, fluid, well, stratigraphic, isotopic, geophysical, or seismic data under an explicitly selected model.

Fraction modern

Fraction modern C-14 (F14C), e.g. 0.5 for one half-life.

Half-life

C-14 half-life in years.

Convert a fraction-modern C-14 measurement into a radiocarbon age in years BP. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Age (yr BP)

Radiocarbon age in years before present (BP).

• Radiometric ages require the correct decay constants, isotopic ratios, standards, common-component correction, closure interpretation, initial composition, and analytical uncertainties. Disturbance, inheritance, diffusion, alteration, and model choice can make a calculated number differ from the geological event age.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Compare independent measurements and models, retain units and analytical metadata, propagate uncertainty, and validate interpretations against logs, cores, maps, laboratory data, or field observations.

• Geologic Time Scale Lookup

  Map an age in millions of years ago (ICS boundaries) to its Phanerozoic plus Ediacaran period, era and boundary ages; boundary ages belong to the younger period.

• Geology Lu Hf Isochron Calculator

  Fit a two-point Lu-Hf isochron and convert its slope to an age using the Lu-176 decay constant.

• Geology Rb Sr Isochron Calculator

  Fit a two-point Rb-Sr isochron and convert its slope to an age using the Rb-87 decay constant.