I) Your first question How is Kali Yuga's age 432, 000 years?
- In the Rig Veda[10.72.1] a yuga refers to generations, a long period, a very brief period, or yoke (joining of two things).
- The names "Yuga" and "Age" commonly denote a Chatur Yuga(चतुर्युग), a cycle of four world ages which are: Krita Yuga, Treta Yuga, Dvapara Yuga and Kali Yuga.
- Seventy-one Caturyugas make a Manvantara (or period of a Manu) [Vishnu Smriti 20.11]..
- A thousand Caturyugas make a Kalpa [Vishnu Smriti 20.12].
- A kalpa is a day of Brahma [Vishnu Smriti 20.13].
- What is Sāvana Varsha(सावन वर्ष/Human Year)? A sāvana year consists of 360 days (1 day = 24 hours).
- What is Deva Varsha(देव वर्ष/Divine Year)? A deva varsha (An year of Devas or Gods) is defined as 360 sāvana (human) years.
- What is definition of Kali Yuga(कलि युग)? According to Vishnu Smriti [20.6], The kaliyuga itself consists of 1000 years only; but is preceded and followed by a twilight lasting 100 years. Its is similar to other three Yugas [2000, 3000 and 4000 for Dvapara, Treta, Krita yugas respectively].
- What is duration of Kali Yuga(कलि युग)? Kali Yuga (the fourth age in a cycle) lasts for 1,200 divine years = Yuga Sandhya + Main Period + Yuga Sandhya = 100 + 1000 + 100 = 1,200 divine years. Therefore, duration of Kali Yuga is 1,200 * 360 = 432,000 sāvana (human) years.
The connection between Bhagavān Vishnu’s Dasāvatāra(दशावतार) to Yuga duration Computation: In krita yuga four avatāras (matsya, kūrma, varāha and narasimha), in treta yuga three avatāras (vāmana, parasurāma and rāma), in dvāpara yuga two avatāras (balarāma and krishna) and kali yuga one avatāra (kalki which will be assumed at the end of kali yuga).
Let us call duration of kali yuga 432,000 sāvana (human) years as Yuga Factor.
- Duration of Kali Yuga = Number of Avataras * Yuga Factor = 1 * 432,000 = 432, 000 sāvana years.
- Duration of Dvāpara Yuga = Number of Avataras * Yuga Factor = 2 * 432,000 = 864, 000 sāvana years.
- Duration of Treta Yuga = Number of Avataras * Yuga Factor = 3 * 432,000 = 1,296, 000 sāvana years.
- Duration of Krita Yuga = Number of Avataras * Yuga Factor = 4 * 432,000 = 1,728, 000 sāvana years.
- Duration of Chatur Yuga = Dasāvatāra * Yuga Factor = 10 * 432,000 = 4,320,000 sāvana years.
Beware-1: This above table establishes the connection between Bhagavān Vishnu’s Dasāvatāra and duration of Chaturyuga(चतुर्युग). By remembering the Yuga Factor which is 432,000 sāvana years(1,200 divine years), the duration of four yugas can be arrived at mentally by multiplying “Yuga Factor” with “Number of Avadāras” assumed by God Vishnu in that particular yuga. Refer the above figure to know the Number of Avadāras assumed in that yuga.
II) Your second and final question As we know, the "Mahabharata" happened around 5,000 years ago and the "Ramayana" happened around 18,000 to 20,000 ago(according to google). So, if the age of "dvapara yug" is around 850,000 years, then the "Ramayana" should be happened around "850,000 + 5,000" years ago. Someone please clear my confusion.
Bhagavān Krishna's death marks the end of Dvāpara Yuga(द्वापर युग) and the start of Kali Yuga(कलि युग), which is dated to 17/18 February 3102 BCE. Lasting for 432,000 years(1,200 divine years/देव वर्ष), Kali Yuga began 5,125 years ago and has 426,875 years left as of 2024 CE. Kali Yuga will end in the year 428,899 CE.
Dvāpara Yuga beginning = Kali Yuga Beginning + Dvāpara Yuga Duration = 5,125 + 864,000 = 869,125.
Treta Yuga beginning = Dvāpara Yuga Beginning + Treta Yuga Duration = 869,125 + 1,296,000 = 2,165,125.
With reference to present year (2024 CE), the beginning of Treta Yuga and Dvāpara Yuga are as follows:
As of 2024 CE, Treta Yuga began 2,165,125 sāvana years ago.
As of 2024 CE, Dvāpara Yuga began 869,125 sāvana years ago.
Conclusion:
Beware-2: Assumption is Dvāpara Yuga begins soon after after Sri Rama's demise.
Beware-3: If someone comes out with accurate data for Sri Rama's demise, then he/she is most welcome and please comment about it.
Assume that Sri Rama ruled 11,000 years and then add just 100 years, then Rāmāyanam (birth of Sri Rama) began approximately 11,100 years before beginning of Dvāpara Yuga.
As of 2024 CE, Rāmāyanam began (869,125 + 11,100) at least 880,225 sāvana years ago.