How long did the precambrian era last?
The Precambrian Era began with the formation of Earth 4.6 billion years ago and lasted until about .6 billion years ago.
The Precambrian covers somewhere between 80%-90% of the entire history of the Earth. It is the longest era in Earth's existence and is considered a Supereon because it is divided further into several eons. The three eons are known as the Hadean, the Archean and the Proterozoic. The Precambrian Era ended .6 billion years ago when hard-spelled creatures began appearing, starting the current era we are in, the Phanerozoic Era.