Carbon-14 Dating Calculator

Carbon dating is a radiometric dating method that uses the decay of carbon-14 to estimate the age of organic materials up to about 50,000 years old. It measures how much C-14 remains in a sample compared to modern levels.

Living organisms constantly exchange carbon with the atmosphere, maintaining steady C-14 levels. When they die, C-14 begins to decay with a half-life of 5,730 years. By measuring remaining C-14, we can calculate how long ago the organism died.

Carbon dating is generally accurate within ±50-100 years for samples up to 20,000 years old. Accuracy decreases with older samples due to lower C-14 levels and potential contamination. Calibration curves help correct for atmospheric variations.

Carbon dating is effective for samples up to about 50,000 years old. Beyond this age, too little C-14 remains for accurate measurement. For older samples, other radiometric dating methods like potassium-argon dating are used.

'Years BP' means 'years Before Present,' with 'Present' defined as 1950 CE. This standard reference point was chosen because atmospheric nuclear testing after 1950 significantly altered atmospheric C-14 levels.

Willard Libby originally calculated C-14's half-life as 5,568 years in the 1940s. Modern measurements show it's actually 5,730 years. Many labs still use the Libby half-life for consistency with older data.

Carbon dating works on organic materials that once lived: wood, charcoal, bone, shell, leather, hair, and plant fibers. It cannot date rocks, metals, or other inorganic materials that never contained living carbon.

Select your input type (fraction remaining, % modern carbon, or activity ratio), enter the measured value, choose the appropriate half-life, and click calculate. The tool will compute the sample's age in years BP and estimated calendar year.