The four Yugas form a descending cycle of cosmic quality — each age shorter and more degraded than the one before, as dharma progressively diminishes. The Mahābhārata's image: a bull of Dharma stands on four legs in the Kṛta Yuga; one leg is removed at each Yuga transition until only one leg remains in Kali Yuga. The cycle then ends in complete dissolution (Pralaya), from which a new Mahāyuga begins.
| Yuga | Duration (human years) | Dharma | Characteristic | Primary practice |
|---|---|---|---|---|
| Kṛta / Satya Yuga | 1,728,000 years (+ 172,800 sandhyā) | 4 legs — full | Universal virtue; humans live 100,000 years; no disease; meditation is the highest practice; no temples needed (all beings naturally abide in Brahman) | Tapas (austerity) |
| Tretā Yuga | 1,296,000 years (+ 129,600 sandhyā) | 3 legs — 75% | Sacrifice and ritual become necessary as virtue begins to decline; human lifespan 10,000 years; the age of Rāma | Yajña (sacrifice) |
| Dvāpara Yuga | 864,000 years (+ 86,400 sandhyā) | 2 legs — 50% | Vedas divided and partially forgotten; disease and conflict appear; human lifespan 1,000 years; the age of Krishna and the Mahābhārata | Archanā (worship) |
| Kali Yuga | 432,000 years (+ 43,200 sandhyā) | 1 leg — 25% | Rapid decline; human lifespan 100 years; widespread sin, hypocrisy, conflict; but also the most accessible liberation: the Name alone suffices. Duration 432,000 years (we are ~5,126 years in) | Kīrtana (chanting the Name) |
The Sandhyā periods — the twilight years
Each Yuga has a sandhyā (twilight dawn) at the beginning and a sandhyāṃśa (twilight dusk) at the end — each one-tenth the length of the Yuga. The four Yugas proper, without sandhyās, total 4,320,000 years (one Mahāyuga). With sandhyās: Kṛta (1,728,000 + 172,800 × 2) = 2,073,600; Tretā (1,296,000 + 129,600 × 2) = 1,555,200; Dvāpara (864,000 + 86,400 × 2) = 1,036,800; Kali (432,000 + 43,200 × 2) = 518,400. Total Mahāyuga with sandhyās: 4,320,000 divine years = 4,320,000 × 360 human years = 1,555,200,000 human years (the Vishnu Purāṇa's calculation). Source: Plofker (2009); Vishnu Purāṇa.
The Kali Yuga — not only degradation
The tradition's account of the Kali Yuga is not simply pessimistic. Multiple Purāṇic passages (particularly the Bhāgavata Purāṇa, BhP 12.3.51-52) specify a remarkable feature of the Kali Yuga: kaler doṣa-nidhe rājann asti hy eko mahān guṇaḥ / kīrtanād eva kṛṣṇasya mukta-saṅgaḥ paraṃ vrajet — "O King, although the Kali Yuga is an ocean of faults, there is one great quality in it: simply by chanting the Name of Krishna, a person becomes free from material attachment and goes to the supreme destination." The shortened lifespan and reduced capacity make intensive austerity impractical — but the Name requires no special qualification. Source: Flood (1996); Bryant (2003).
The tradition's cosmic time scale is the most ambitious in any pre-modern religious cosmology — dwarfing both Biblical chronology (6,000 years) and the ancient Greek cosmologies. The numbers are not accidental: they are built on a precise mathematical system in which each unit is exactly 360 times the previous one (paralleling the 360-degree circle and the 360-day Vedic year).
The 14 Manus — progenitors of humanity
Each Manvantara is presided over by a Manu — the first human being and lawgiver of that era. The 14 Manus of the current Kalpa: (1) Svāyambhuva (from Brahmā himself); (2) Svārociṣa; (3) Uttama; (4) Tāmasa; (5) Raivata; (6) Cākṣuṣa; (7) Vaivasvata (current — Manu Vaivasvata, the Noah-figure of the flood narrative and ancestor of the Solar dynasty of Rāma); (8) Sāvarṇi (future); (9–14) five more future Manus. Each Manu establishes the Dharma and the social structure of his era. The Manusmṛti is attributed to Vaivasvata Manu — the current Manu, lawgiver of our era. Source: Vishnu Purāṇa; Olivelle (2005).
The Pralaya — cosmic dissolution
The tradition distinguishes four types of Pralaya (dissolution): Naimittika Pralaya (occasional dissolution — at the end of each Kalpa/Brahmā's day; Brahmā sleeps and the manifested cosmos dissolves into unmanifest Prakṛti; but Brahmā himself and the subtle bodies of advanced souls persist); Prākṛtika Pralaya (elemental dissolution — at the end of Brahmā's life; all matter, energy, and subtle elements dissolve back into Avyakta/unmanifest Prakṛti); Ātyantika Pralaya (final dissolution for the individual — liberation/Mokṣa; the individual soul's dissolution into Brahman, from which it does not return); Nitya Pralaya (constant dissolution — the ongoing moment-to-moment dissolution of each moment of experience into the past). Source: Vishnu Purāṇa; Flood (1996).
The theological meaning of cyclical time
The Yuga system is not simply a cosmological model but a theological statement. Its key claims: (1) History does not progress linearly toward a unique end-point but cycles through descending and ascending ages; (2) The current era (Kali Yuga) is a period of decline, which provides the theological basis for the tradition's emphasis on accessible, non-demanding practices (the Name, simple devotion); (3) The decline is not permanent — after the Kali Yuga's 432,000 years, a new Kṛta Yuga of universal virtue will begin; (4) The individual's liberation (Ātyantika Pralaya) is independent of the cosmic cycle — a person can achieve Mokṣa in any Yuga, regardless of the cosmic moment. Source: Flood (1996); Bryant (2003).
Scholarly debate — literal or metaphorical?
Modern scholarship is divided on how to interpret the Yuga system. The traditional view (held by orthodox communities): the numbers are literally correct and describe actual cosmic history. The reformist view (Swami Vivekananda, Sri Yukteswar in The Holy Science): the numbers are symbolic, or the Yugas are far shorter cycles (Sri Yukteswar proposed a 24,000-year cycle based on the precession of the equinoxes). The academic view (Plofker, Flood): the Yuga system is a mathematical-cosmological framework that encodes specific theological commitments (the descent of dharma, the accessibility of liberation in the current age) regardless of its literal accuracy. All three approaches engage seriously with the system's internal logic. Source: Plofker (2009); Flood (1996).