The exact calculations of the age of Brahma and the existing manvantar according to the Bhagwatam.Absolute age of the earth planet and the sun. Bhagwan Ved Vyas explains in the Bhagwatam that 155.52 trillion years have passed since Brahma originally created this planetary system, and this is the present age of Brahma.
The Bhagwatam says, “Brahma’s one day equals to 1,000 cycles of the four yugas (one cycle of four yugas is 4.32 million years). It is called one kalp. There are fourteen Manus in one kalp. For the same length of time there is the night of Brahma. This is called pralaya or kalp pralaya. At that time the earth planet and the sun along with three celestial abodes (bhu, bhuv and swah) enter into the transition period (and become uninhabited). During that period Brahma holds within himself all the beings of the material and the celestial worlds in a suspended state and sleeps. (The next day he again produces them and re-forms them as they were before.) In this way Brahma lives for two parardh (twice of 50 years). After that, there is a complete dissolution of the brahmand (the planetary system and its celestial abodes). This is called prakrit pralaya of the brahmand.” (Bhag. 12/4/2 to 6)
“Half of Brahma’s life is called parardh. One parardh is finished and the existing kalp is in the beginning of the second parardh (the first day of the 51st year of Brahma). The very first day of Brahma was the day when he himself was created by God Vishnu and it was called the Brahm kalp. The present running kalp is called Varah kalp (or Shvet Varah kalp).” (3/11/33,34,36)
“In this kalp six Manus like Swayambhuva Manu etc. have elapsed. The seventh Manu is the son of Vivaswan. He is the present Manu and is called Vaivaswat Manu.” (8/1/4; 8/13/1)
In the Bhagwat Mahatmya Bhagwan Ved Vyas reveals a great secret and says that this is the 28th dwapar (of Vaivaswat manvantar). Not in all, but sometimes at the end of the 28th dwapar of a kalp the supreme personality of God, Krishn, in His absolute loving form descends in the world on the land of Bharatvarsh and reveals His supremely charming playful Divine leelas; and that had happened in our age just about 5,000 years ago. (Bhag. Ma. 1/29)
According to the above information, Brahma’s age which is also the absolute age of our sun and the earth planet is: 50 years of Brahma x 720 days and nights x (1,000 x 4.32 million years of the four yugas, which is one day of Brahma) + 1,972 million years* (the existing age of the earth planet) = 155.521972 trillion years.
* One manvantar is: 308.57142 million years. Thus, 1851.4285 (6 manvantar) + 116.6400 (27 cycles of four yugas) + 3.8931 (the three yugas and the elapsed time of kaliyug) = 1971.9616 in 1998 AD.
One year of Brahma is of 360 days (and one month of Brahma is of 30 days). So, 360 x 50 = 18,000 days and nights of Brahma have elapsed. Thus, our earth planet and the sun have already been renovated 18,000 times. It’s a big figure, but reasonable if you think over it deeply, and again it is given by an all-knowing Divine personality.