Relative age is the age of a rock layer (or the fossils it contains) compared to other layers. Absolute age is the numeric age of a layer of rocks or fossils. Absolute age can be determined by using radiometric dating.

What is the equation used in absolute dating?

To determine the absolute age of this mineral sample, we simply multiply y (=0.518) times the half life of the parent atom (=2.7 million years). Thus, the absolute age of sample = y * half-life = 0.518 * 2.7 million years = 1.40 million years.