There are 71 Maha-yugas in a Manvantara (1 life span of Manu) and 14 Manvantara in a day of Brahma
71 Catur-yugas or Maha-yugas = 1 Manvantara (1 life span of Manu)
14 Manvantaras = 1 kalpa (One, 12 hour day-time of Brahma)
So we have already passed through the previous 6 Manvantaras in Brahma's day.
We are in the 460th Maha-yuga making it about 11.40 am during Brahma's day-time. There are 1000 Maha-yugas in Brahma's 12 hour day-time
A Catur yuga, Dvipa yuga and Maha yuga - ''A cycle of 4 Yugas''.
The Catur-yuga is also known as Divya-yuga or Maha-yuga and is made up of the four yugas -
''Satya- yuga, Treta-yuga, Dvapara-yuga, Kali-yuga''.
There are 1000 Catur-yuga or Maha-yugas in the 12 hour day-time of Lord Brahma (that takes 4 billion 320 million human years)
While there are NO Catur-yugas or Maha-yugas in Brahma's 12 hour night-time (that also takes 4 billion 320 million human years) while Brahma sleeps as a partial annihilation takes place.
However, it is said both Lord Krishna in His original form and Lord Caitanya only come ''once'' in a day of Brahma, that ''day'' really means a ''day and night 24 hour period of Brahma'' that together over 24 hours takes 8 billion 640 million human years.
Presently ''our Kali-yuga'' where Lord Caitanya also came is happening in the very early morning of Brahma's ''day-time''
We are presently nearly half way into Brahma's 12 hour day-time which is the late morning being in the 454th Maha-yuga or Chatur-yuga out of a 1000.
Brahma's full day-time period of 12 hours takes 4 billion 320 million human years to happen.
Then night-time comes which is also 4 billion 320 million human years long.
At night while Brahma sleeps and creates no Chatur-yuga or Maha-yugas, our Universe is partially annihilated.
When the next day-time arrives at sunrise the cycle repeats itself for every day and night of Brahma's life
We are in the 28th Chatur-yugas or Maha-yuga in the ''Vaivasvata Manu'' (current) that has 71 Maha-yugas in it.
71 Chatur-yugas = 1 Manvantara (1 life span of Manu)
14 Manvantaras = 1 kalpa (1 day-time of Brahma)
We are in the 460th Maha-yuga also known as a Chatur-yuga
1 Svayambhuva Manu
2 Svarocisha Manu Vibhu
3 Uttama Manu Satyasena
4 Tapasa Manu Hari
5 Raivata Manu Vaikuntha
6 Cakshusha Manu Ajita
7 Vaivasvata Manu (current) Vamana
8 Savarni Manu Sarvabhauma
9 Daksha-savarni Manu Rishabha
10 Brahma-savarni Manu Vishvaksena
11 Dharma-savarni Manu Dharmasetu
12 Rudra-savarni Manu Sudama
13 Deva-savarni Manu Yogesvara
14 Indra-savarni Manu Brihadbhanu
There are 2 Kalpas in Brahma's full day of 24 hours not 1
1 kalpa for his 12 hour day
1 kalpa for his 12 hour night
A Catur yuga, Dvipa yuga and Maha yuga - ''A cycle of 4 Yugas''.
The Catur-yuga is also known as Divya-yuga or Maha-yuga and is made up of the four yugas -
''Satya- yuga, Treta-yuga, Dvapara-yuga, Kali-yuga''.
There are 1000 Catur-yuga or Maha-yugas in the 12 hour day-time of Lord Brahma (that takes 4 billion 320 million human years)
While there are NO Catur-yugas or Maha-yugas in Brahma's 12 hour night-time (that also takes 4 billion 320 million human years) while Brahma sleeps as a partial annihilation takes place.
However, it is said both Lord Krishna in His original form and Lord Caitanya only come ''once'' in a day of Brahma, that ''day'' really means a ''day and night 24 hour period of Brahma'' that together over 24 hours takes 8 billion 640 million human years.
At night while Brahma sleeps and creates NO Chatur-yuga or Maha-yugas, our Universe is partially annihilated.
When the next day-time arrives at sunrise the cycle repeats itself for every ''day and night'' of Brahma's life
Taken from here