Four Yugas - Durations of Four Yugas

Durations of Four Yugas

According to the Laws of Manu, one of the earliest known texts describing the yugas, the length is 4800 years + 3600 years + 2400 years + 1200 years for a total of 12,000 years for one arc, or 24,000 years to complete the cycle (one precession of the equinox). There is no mention of a year of the demigods or any year longer than the solar year, which is consistent with description in The Holy Science. However, the more recent and popular interpretation from the Srimad Bhagavatam states the following: "The duration of the Satya millennium equals 4,800 years of the years of the demigods; the duration of the Dvāpara millennium equals 2,400 years; and that of the Kali millennium is 1,200 years of the demigods... As aforementioned, one year of the demigods is equal to 360 years of the human beings. The duration of the Satya-yuga is therefore 4,800 x 360, or 1,728,000 years. The duration of the Tretā-yuga is 3,600 x 360, or 1,296,000 years. The duration of the Dvāpara-yuga is 2,400 x 360, or 864,000 years. And the last, the Kali-yuga, is 1,200 x 360, or 432,000 years in total." (Śrīmad Bhāgavatam 3.11.19) . These 4 yugas follow a timeline ratio of (4:3:2:1).

The ages see a gradual decline of dharma, wisdom, knowledge, intellectual capability, life span, emotional and physical strength.

• Satya Yuga:- Virtue reigns supreme. Human stature was 21 cubits. Average human lifespan was 100,000 years.
• Treta Yuga: - There was 3 quarter virtue & 1 quarter sin. Normal human stature was 14 cubits. Average human lifespan was 10,000 years.
• Dwapar Yuga: - There was 1 half virtue & 1 half sin. Normal human stature was 7 cubits. Average human lifespan was 1000 years.
• Kali Yuga: - There was 1 quarter virtue & 3 quarter sin. Normal human stature was 3.5 cubits. Average human lifespan will be 100 years. Towards the end of the Yuga this will come down to 20 years.

While the long yuga count is the most popular it does not correlate to any known celestial motion found in the Astronomical Almanac. The value of 24,000 years is within 7% of the modern astronomical calculation of one full precession of the equinox of 25,772 years. This phenomenon is observed as the stars moving retrograde across the sky at about 50 arc seconds per year and is thought to produce periods of warm ages and ice ages known as the Milankovitch cycle, thus the yuga cycle may have some basis in known terrestrial cycles.