Astrology is based on complex mathematical calculations involving planetary positions, astronomical coordinates, and time cycles. The core calculations involve:

1. Natal Chart (Birth Chart) Calculation

A natal chart is a snapshot of the sky at the exact time and place of a person's birth. It involves:

Date, Time, and Location of Birth – Determines planetary positions.

Zodiac Sign (Sun Sign & Moon Sign) – Based on the position of the Sun and Moon.

Ascendant (Rising Sign) – The zodiac sign rising on the eastern horizon at birth.

Houses (12 Divisions) – The sky is divided into 12 sections, each representing aspects of life (e.g., career, relationships).

2. Planetary Positions & Ephemeris

Astrologers use an ephemeris (a table of planetary positions) to determine where planets were at the time of birth. These positions are mapped using:

Ecliptic Coordinates – Based on the Earth's orbit around the Sun.

Sidereal or Tropical Zodiac System – Defines how planetary positions align with star constellations.

3. Aspects (Angles Between Planets)

Planets form angles (aspects) with each other, influencing their effects.

Key aspects:

Conjunction (0°) – Strong fusion of energies.

Opposition (180°) – Conflict or balance.

Trine (120°) – Harmony and ease.

Square (90°) – Challenge and tension.

Sextile (60°) – Opportunities.

4. Transits & Progressions

Transits: How current planetary movements interact with the birth chart.

Progressions: A method that advances the natal chart over time to predict life changes.

5. Dasha System (Vedic Astrology)

In Vedic astrology (Jyotish), a person’s life is divided into planetary periods (Dasha).

Based on the Moon's position at birth and planetary cycles (Mahadasha, Antardasha).

6. Numerology & Planetary Influence

Some systems assign numbers to planets and zodiac signs to determine fate and compatibility.