How old is the earth in years

The age of the Earth is estimated to be 4.54 ± 0.05 billion years (4.54 * 109 years ± 1%).[This age may represent the age of the Earth's accretion, of core formation, or of the material from which the Earth formed. This dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.

Following the development of radiometric age-dating in the early 20th century, measurements of lead in uranium-rich minerals showed that some were in excess of a billion years old.[6] The oldest such minerals analyzed to date-small crystals of zircon from the Jack Hills of Western Australia-are at least 4.404 billion years old.[7][8][9] Calcium-aluminium-rich inclusions-the oldest known solid constituents within meteorites that are formed within the Solar System-are 4.567 billion years old,[10][11] giving a lower limit for the age of the Solar System.