How to use the radiometric rock age calculator
Estimate rock age from the daughter-to-parent ratio. Enter daughter / parent ratio, half-life in the fields above; the age is computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- R — Daughter / parent ratio
- th — Half-life (billion years)
Worked example
With daughter / parent ratio = 0.5, half-life = 4.468 billion years, the calculator gives age ≈ 2.613612 billion years.
Frequently asked questions
What is the formula for the radiometric rock age calculation?
Age (billion years) = th × ln(1+R) / ln(2). Here R is daughter / parent ratio, th is half-life (billion years).
What inputs do I need for the radiometric rock age calculator?
You need daughter / parent ratio, half-life in billion years. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.