The Bible doesn’t give the age of planet earth. Biblical scholars don’t know whether this planet was created at the beginning of creation week or if it was already present before the creation week.
But the age of life on earth can be calculated by adding the genealogies of the Bible that are listed in Genesis 5 and 11 from Adam to Abraham. These genealogies add up to 2,000 years. And most Bible scholars agree that Abraham lived about 2,000 B.C. (4,000 years ago). So, this makes the age of life on earth about 6,000 years.
The most famous works for these calculations were conducted by Dr. Floyd Jones in his book “The Chronology of the Old Testament, A.D. 1993” and Archbishop James Ussher in his book “The Annals of the World, A.D. 1658.”
Secular scientists claim that the Earth is about 4.5 billion years old. They base their calculation on radiometric dating and other methods. However, these methods are founded on evolutionary assumptions that are not reliable nor have been proven, therefore, their calculations can’t be accurate.
Cultures around the world had similar calculations to the Biblical ones about the age of humanity. It is noteworthy to add that these calculation are in the thousands of years and not in the millions of years (ex. English and Mayan). The closest one to the Biblical calculation is that of the Irish chronology which has a date of about 4000 from Adam to Christ.
As for the origin of the fossils that are found in the rock layers around the world, this could be easily explained biblically by the flood of Noah (Genesis 6-8). For the flood was fully capable of removing rock layers and re-depositing them in a different location in a very short time collecting in between its layers all kinds of life forms. And the tremendous water force of the gushing elements could have carved canyons and created mountains in a matter of days or weeks (Genesis 7:19).
For scientific evidence for a young earth, please check out: Can you share evidence for the young age of earth?
In His service,