Numerous, independent lines of scientific evidence consistently show that the Earth is approximately 4.54 billion years old. This conclusion is not based on a single measurement but is a robust finding supported by multiple dating techniques and observations from different fields of science. Radiometric dating of meteorites and lunar rocks.
Since the Earth's surface has been reshaped by erosion and plate tectonics, the planet's oldest original rocks have been recycled into the mantle. Scientists therefore look to material from the early solar system to determine the Earth's age.

Meteorites: The most precise dates come from meteorites, which are fragments of asteroids that formed at the same time as the planets. Radiometric dating of meteorites, such as the Canyon Diablo meteorite in Arizona, consistently yields ages around 4.54 to 4.58 billion years. Geochemist Clair Cameron Patterson used uranium-lead dating on the Canyon Diablo meteorite in 1953 to establish the most precise age for the Earth.
Lunar samples: Rocks collected from the Moon's surface during the Apollo missions provide another reliable set of data. Since the Moon lacks plate tectonics, its surface preserves older materials. Radiometric dating of these lunar rocks gives ages of up to 4.51 billion years.

Dating Earth's oldest materials
While the Earth's original crust is gone, scientists have found isolated materials that provide lower bounds for its age.

Zircon crystals: The oldest terrestrial materials found on Earth are tiny zircon crystals from the Jack Hills of Western Australia. These highly durable minerals have been dated to 4.404 billion years old.
Ancient rocks: The oldest known intact rock formations on Earth are found in Greenland, Canada, and Australia, with radiometric ages of up to 4 billion years. These provide a minimum age for the planet's crust.

Geological and astronomical evidence
Beyond direct radiometric dating, other lines of evidence corroborate the vast age of the Earth and the solar system.

Plate tectonics: Measurements of seafloor spreading, where new crust is created, reveal continental drift rates of a few centimeters per year. Extrapolating this rate confirms that the Atlantic Ocean, for instance, took hundreds of millions of years to form as the continents drifted apart.
Ice cores: Annual layers in ice cores drilled in Greenland and Antarctica provide a continuous record of climate history. The oldest sections of these cores show annual layers extending back over 800,000 years, far longer than the several thousand years suggested by young-Earth creationism.
Astrophysics: Observations of the universe provide independent confirmation of deep time. For example, light from distant galaxies has traveled for billions of years to reach us. The expansion rate of the universe and the evolution of stars and galaxies also point to a cosmos that is 13.8 billion years old, consistent with a solar system that formed over 4.5 billion years ago.

All these independent methods, when properly applied, yield consistent and mutually reinforcing results, forming the scientific basis for the Earth's immense age.