What is the duration of the four yugas as mentioned in the Vayu Purana?

"Yathā vedaś catuṣpādaś catuṣpādaṁ tathā yugam।
Yathā yugaṁ catuṣpādaṁ vidhātrā vihitaṁ svayam॥
Catuṣpādaṁ purāṇaṁ tu brahmaṇā vihitaṁ purā॥"

- Vaayu puran (chapter 32.67)

Just as God made the Vedas Chatushpad, similarly, Brahmaji divided each Yuga into four padas (quarters). The names of these four padas are as follows-

1. Prakriya Pada

2. Anushang Pada

3. Upodghat Pada

4. Sanhar Pada

Age of Yuga Explained

Satya Yuga enjoys one pada, Tretayuga enjoys two, Dwapara Yuga enjoys three, and Kaliyuga enjoys four.

So the age of Satya Yuga is 1200 years, Treta Yuga is 2400, Dwapara Yuga is 3600, and 4800 for Kaliyuga, which is made to 5000 years, and the current period is a transformation period to Satya Yuga.

The age of the four Yugas is stated to be 12,000 human years. The word 'Divya' is not used in any verse; human years are used. Hence, it is clear that mysterious changes have been made in the Sanatan scriptures over time.

There is much other evidence, which you can read in detail: Actual Age of Kaliyuga.