Earth is approximately 4.54 billion years old.

Show me why

Earth’s age is inferred from radioactive isotope systems in ancient materials, including meteorites. Earth’s oldest surviving rocks do not by themselves date the beginning of the planet: crust is repeatedly recycled.

A common misconception

Carbon-14 dating is not the method used to date Earth’s formation.

Where the limits are

The age is an estimate with uncertainty. Formation was a process, not an instantaneous event. The older USGS page also contains an outdated universe-age estimate; this entry uses only its Earth-age discussion.

How we know

Radiometric methods compare parent and daughter isotopes using measured decay rates. Agreement among different materials and isotope systems provides a check on the interpretation. The USGS age discussion addresses why meteorites help constrain the time of formation.

Sources you can inspect

1. USGS
   Geologic Time: Age of the Earth

   Explains the 4.54-billion-year estimate and dating evidence.

   Publication date not stated · Checked in initial research 2026-10-08
2. American Chemical Society
   How old is the Earth?

   Explains the radiometric dating method.

   Publication date not stated · Checked in initial research 2026-10-08

Links were located in source research. Some publishers restrict automated access. Source presence is not institutional endorsement. Our citation standard

Revision history

• 2026-10-08Initial AI-assisted source research and scoped explanation. Awaiting owner editorial approval; not publicly verified.
• 2026-10-08Owner explicitly approved all content as created for public publication. Statements, sources and evidence classifications unchanged.