Geologists, based on various dating methods, estimate that the Earth is approximately 4.54 billion years old. This age is determined using a combination of:

* Radiometric dating: This method analyzes the decay of radioactive isotopes in rocks and minerals to calculate their age.

* Meteorite dating: Meteorites are believed to have formed at the same time as the Earth and have similar compositions, providing a reliable reference for age.

* Lunar samples: Samples from the Moon, which formed around the same time as Earth, also contribute to our understanding of the Earth's age.

While the exact age may vary slightly due to the complexities of dating methods, the scientific consensus is that the Earth is approximately 4.54 billion years old.