Yuga means the age or the aeon of the universe. Yugas are described in different ways under various beliefs. In Hindu religious text the time of the universe is divided into Yugas, Mahayugas and Kalpas. There are four Yugas namely, Krita Yuga or Satya Yuga, Treta Yuga, Dwapar Yuga and Kali Yuga. How long are all those a eons? It is incredibly a huge calculation for a human mind. Here goes the lengths of all four Yugas as described in Hindu mythologies. The years are calculated in terms of our years and the years of the gods which have different connotations. Each year of the gods is equivalent to 360 years of men. Hence,
Krita Yuga has 4800 years of gods x 360 equals to 1,728,000 years of ours
Treta Yuga has 3600 years of gods x 360 equals to 1,296,000 years of ours
Dwapar Yuga has 2400 years of gods x 360 equals to 864,000 years of ours. Kali Yuga has 1200 years of gods x 360 equals to 432,000 years of ours
Total number of years of all four Yugas is 4,320,000 years of ours. Total period of all four Yugas becomes one Mahayuga. i. e., 4,320,000 years
Two thousand Mahayugas makes one Kalpa.
One Kalpa is just a day and night for Bramha, the creator. Every time he goes for retiring, he destroys the whole creations except gods, sages and elements. Next day of his, as soon as he gets awake, he again starts his creations for another day of ‘His’ which is equivalent to 2,160,000,000 years of ours.
It is believed that this process goes on for 100 years of Bramha.