Measuring the uranium-to-lead ratios in the oldest rocks on Earth gave scientists an estimated age of the planet of 4.6 billion years. Segment from A Science Odyssey: Origins. Radiometric Dating: Geologists have calculated the age of Earth at 4.6 billion years.

How old is the Earth believe to be?

4.54 billion years old Earth is estimated to be 4.54 billion years old, plus or minus about 50 million years. Scientists have scoured the Earth searching for the oldest rocks to radiometrically date. In northwestern Canada, they discovered rocks about 4.03 billion years old.