Fossil Age Estimator Calculator

Age range from stratigraphic layer and index fossils.

Parent isotope (relative units)

Daughter isotope (relative units)

Dating system (0=C14, 1=K-Ar, 2=U-Pb, 3=Rb-Sr)

Sediment depth (meters)

Sedimentation rate (m/kyr)

Tab to move between fields

Radiometric age (years)

5,730

Stratigraphic age (years)1,000,000

Parent remaining (%)50

Half-lives elapsed1

D/P ratio1

Geologic era code0

How to Use This Calculator

Select the Dating system: 0 for Carbon-14 (up to ~50,000 yr), 1 for K-Ar (millions of years), 2 for U-Pb or 3 for Rb-Sr (billions of years).
Enter the measured Parent isotope amount and Daughter isotope amount in consistent relative units (e.g., ppm or counts).
Set Sediment depth (m) and Sedimentation rate (m/kyr) for an independent stratigraphic age cross-check.
Compare the Radiometric age and Stratigraphic age outputs — agreement between methods increases confidence.
The Geologic era code and Percent parent remaining help place the sample in its geologic context.

How the result changes with Parent isotope (relative units)

Parent isotope (relative units)	Radiometric age (years)
100	3,351.84
350	1,103.86
650	612.62
900	446.95

Parent isotope (relative units): Measured amount of the parent (radioactive) isotope in relative units.
Daughter isotope (relative units): Measured amount of the daughter (decay product) isotope.
Dating system (0=C14, 1=K-Ar, 2=U-Pb, 3=Rb-Sr): Isotope system: 0=Carbon-14 (5,730 yr), 1=Potassium-Argon (1.25 Gyr), 2=Uranium-Lead (4.47 Gyr), 3=Rubidium-Strontium (48.8 Gyr).
Sediment depth (meters): Depth of the fossil within the sedimentary column.
Sedimentation rate (m/kyr): Average rate of sediment accumulation in meters per thousand years.

Radiometric age (years): Estimated age from parent-daughter isotope ratio and decay constant.
Stratigraphic age (years): Independent age estimate from sediment depth and deposition rate.
Parent remaining (%): Percentage of the original parent isotope still present.
Half-lives elapsed: Number of half-life periods that have passed.
D/P ratio: Daughter-to-parent isotope ratio used in the age calculation.
Geologic era code: 0=Recent, 1=Quaternary, 2=Neogene, 3=Paleogene, 4=Cretaceous, 5=Older.

Identify Input Parameters
4 parameters
Parent isotope (relative units) = 50, Daughter isotope (relative units) = 50, Dating system (0=C14, 1=K-Ar, 2=U-Pb, 3=Rb-Sr) = 0, Sediment depth (meters) = 10 = 5 input(s) provided
Calculate Radiometric age
5730 = 5730
Calculate Stratigraphic age
Stratigraphic age = stratigraphicAgeKyr * 1000
1000000 = 1000000
Calculate Parent remaining
Parent remaining = (parentAmount / (parentAmount + daughterAmount)) * 100
50 = 50