Brahma (ब्रह्मा) - also known as "The Creator" is one of the three Gods of Hinduism viz Brahma, Vishnu and Shiva. Brahma, Vishnu and Shiva are brothers and Brahma is the eldest amongst them. Brahma is endowed with "Rajguna". By the virtue of this "Rajguna" the living beings on earth produce offsprings and the act of creation continues.
Age of Brahma
Brahma's age is of 100 years (Divine years) duration.
Calcualtion of a "Divine year"
One chaturyug (four yugas - Satyuga, Tretayuga, Dwaparyuga, Kalyuga) is made up of 4320000 years (forty three lakh twenty thousand years or 4 million 320 thousand years)
One day of Brahma = 1000 (one thousand) chaturyug (four yugas) =
1000 X 4320000 = 4320000000 earth years (4 billion 320 million years).
One night of Brahma = 1000 (one thousand) chaturyug (four yugas).
Therefore one full day of Brahma is made of 2000 chaturyugas.
One year of Brahma or "One Divine year" = 2000 X 30 (days) X 12 (months) = 720000 chaturyugas = 3110400000000 earth years (3 trillion 110 billion 400 million years)
Age of Brahma = 100 "Divine years" = 100 X 720000 chaturyugas = 72000000 chaturyugas = 311,040,000,000,000 earth years (311 trillion 40 billion earth years)