Kalpa (Sanskrit: कल्प kalpa) is a Sanskrit word meaning a relatively long period of time (by human calculation) in Hindu and Buddhist cosmology.
Generally speaking, a kalpa is the period of time between the creation and recreation of a world or universe. The definition of a kalpa equaling 4.32 billion years in the Puranas—specifically Vishnu Purana and Bhagavata Purana.
The duration of the material universe is limited. It is manifested in cycles of kalpas. A kalpa is a day of Brahmā, and one day of Brahmā consists of a thousand cycles of four yugas, or ages: Satya Yuga, Treta Yuga, Dvapara Yuga and Kali Yuga. The cycle of Satya is characterized by virtue, wisdom and religion, there being practically no ignorance and vice, and the yuga lasts 1,728,000 years. In the Tretā-yuga vice is introduced, and this yuga lasts 1,296,000 years. In the Dvāpara-yuga there is an even greater decline in virtue and religion, vice increasing, and this yuga lasts 864,000 years. And finally in Kali-yuga (the yuga we have now been experiencing over the past 5,000 years) there is an abundance of strife, ignorance, irreligion and vice, true virtue being practically nonexistent, and this yuga lasts 432,000 years.
In Kali-yuga vice increases to such a point that at the termination of the yuga the Supreme Lord Himself appears as the Kalki avatāra, vanquishes the demons, saves His devotees, and commences another Satya-yuga. Then the process is set rolling again.
These four yugas, rotating a thousand times, comprise one day of Brahmā, and the same number comprise one night.. According to the Mahabharata, 12 months of Brahma (=360 days) constitute his year, and 100 such years are the life cycle of the universe. Brahmā lives one hundred of such "years" and then dies. 100 such years of "Brahma" is called a "Maha-Kalpa". These "hundred years" total 311 trillion 40 billion (311,040,000,000,000) earth years. Fifty years of Brahma are supposed to have elapsed, and we are now in the fifty-first.
A Satya Yuga = 1,728,000 Earth years
A Treta Yuga = 1,296,000 Earth years
A Dwapara Yuga = 864,000 Earth years
A Kali Yuga = 432,000 Earth years
A Mahayuga = Satya +Treta + Dwapara + Kali Yugas = 4,320,000 Earth Years
A Manvantara = 71 Yuga Cycles (Satya, Treta, Dwapara & Kali Yugas) with Sandhikala
A Sandhikala = Equal to the length of a Satya-yuga (1,728,000) years
A Kalpa = 1,000 Chaturyuga = 4.32 Billion Earth Years
One day of Brahma = One Thousand Mahayuga = 14 Manvantaras + 15 Sandhikalas
Two such Kalpa = Day and Night of Brahma
1 Day of Brahma = 2 Kalpa's = 4.32 X 2 Billion Earth Years = 8.64 Billion Earth Years
A month of Brahma = 30 days of Brahma (Day and Night) = 60 Kalpa
30 Days of Brahma = 30 X 8.64 Billion Earth Years = 259.2 Billion Earth Years
1 Years of Brahma = 360 Brahma Days = 8.64 Billion Years X 360 = 3110.4 Billion Earth Years
A Mahakalpa = 100 Years of Brahma = 311, 000.4 Billion Earth Years
8000 such "Maha-Kalpa"-s form one "Yuga of Brahma", whose length is 2.4 Quintillion years. There are other greater cycles whose lengths are 22.3 Sextillion years, 670 Sextillion years and 201 Septillion years respectively.
By these calculations the life of Brahmā seems fantastic and interminable, but from the viewpoint of eternity it is as brief as a lightning flash. In the Causal Ocean there are innumerable Brahmās rising and disappearing like bubbles. Brahmā and his creation are all part of the material universe, and therefore they are in constant flux.
This much knowledge in Puranas, really beyond imagination.
