Analyze fossil samples with reliable decay calculations. Compare ratios, percentages, and ages in one form. Download reports quickly for study notes, audits, and sharing.
| Sample | Remaining Carbon-14 (%) | Fraction Modern | Approximate Age (years BP) |
|---|---|---|---|
| Recent organic sample | 100 | 1.00 | 0 |
| Charcoal fragment | 75 | 0.75 | 2380 |
| Bone collagen | 50 | 0.50 | 5730 |
| Buried wood | 25 | 0.25 | 11460 |
| Ancient peat sample | 10 | 0.10 | 19035 |
Decay constant: λ = ln(2) / T1/2
Radiocarbon age: t = -ln(F) / λ
From percentage input: F = P / 100
From activity ratio: F = A / A0
Estimated calendar year: Reference Year - t
In this calculator, F is the fraction modern carbon, T1/2 is the half-life, and t is the estimated radiocarbon age in years before present.
A carbon dating fossils calculator helps estimate the age of once-living remains. It uses carbon-14 decay. This isotope slowly breaks down after death. Living organisms exchange carbon with the atmosphere while alive. That exchange stops at death. The remaining carbon-14 then decreases at a known rate.
This tool converts a measured carbon ratio into an age estimate. You can enter remaining percentage, fraction modern, or activity ratio. The calculator then finds the decay constant, elapsed half-lives, years before present, and an estimated calendar year. This helps with lab review, field notes, and physics study.
The default half-life is 5,730 years. That value is widely used in radiocarbon work. If your workflow uses another value, you can change it. Small changes in the carbon fraction can shift the result. That is why the calculator also allows uncertainty testing.
A higher fraction modern means a younger sample. A lower fraction means an older sample. The years BP value uses a reference year, usually 1950. The calendar estimate is a simple subtraction from that reference point. It is useful for quick interpretation. Real laboratory dating may also require calibration curves and contamination checks.
Use this carbon dating fossils calculator for charcoal, bone collagen, wood, peat, and other once-living materials when radiocarbon assumptions apply. It supports archaeology, paleontology, geology, and classroom physics. It is not suitable for igneous rocks or very old non-organic samples. Carbon dating works best inside the normal radiocarbon range.
This tool gives fast and transparent fossil age estimates. It turns measured ratios into clear age values. It also creates exportable records for reports and study files. For publication-level dating, always compare results with calibrated lab data and documented sample conditions.
BP means before present, and present is defined as 1950 in radiocarbon dating. So a result of 3,000 years BP means about 3,000 years before 1950.
Yes. Select the percentage mode and enter the remaining carbon-14 percent. The calculator converts that value into fraction modern automatically before calculating the age.
Carbon-14 decays over time after death. Less remaining carbon-14 means more decay has happened. More decay means more time has passed since the organism stopped exchanging carbon.
It is the common default for radiocarbon dating calculations. Some workflows may use different conventions or calibration practices. This calculator lets you change the value when needed.
No. The result is an estimate based on measured carbon data and chosen assumptions. Real dating accuracy also depends on contamination, calibration, sample quality, and lab methods.
No. Carbon dating only works for materials that were once alive and still contain measurable radiocarbon. It is not suitable for most rocks, metals, or extremely ancient samples.
Fraction modern is the sample’s carbon-14 level compared with a modern reference standard. A value of 1 means modern level. A value of 0.5 means half remains.
Uncertainty gives a more realistic age range. Small changes in measured carbon can shift the final answer. Adding uncertainty helps compare results with lab reports and scientific notes.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.