Free Astrology Calculators
Explore our free, professional-grade astrology calculators — birth chart, synastry, Vedic (Jyotish), Chinese BaZi, and transits — with arc-second-accurate ephemeris data and interactive 3D visualization.
Available Calculators
Birth Chart Calculator
Generate your complete natal chart with precise planetary positions at your exact time and place of birth. Discover your Sun, Moon, Rising signs, and all planetary placements in houses and signs.
- Precise planetary positions using Swiss Ephemeris
- All major celestial bodies including asteroids
- Multiple house systems (Placidus, Whole Sign, Equal, Koch)
Synastry Calculator
Compare two birth charts to discover relationship compatibility. Analyze the planetary aspects between partners to understand attraction, challenges, and long-term potential.
- Bi-wheel chart overlay visualization
- Inter-chart aspect analysis
- Composite chart generation
Vedic Astrology Calculator
Calculate your Vedic birth chart with accurate sidereal positions. Includes Nakshatra placements, Vimshottari Dasha periods, planetary yogas, and traditional Jyotish analysis.
- True sidereal zodiac (Lahiri ayanamsa)
- 27 Nakshatra calculations with padas
- Vimshottari Dasha timeline
BaZi Calculator
Generate your Chinese Four Pillars of Destiny chart. Discover your Day Master, analyze the balance of five elements, and understand your luck cycles through the Ten-Year Pillars.
- Four Pillars (Year, Month, Day, Hour)
- Day Master strength analysis
- Five Element balance chart
Transit Calculator
Track current planetary transits and see how they aspect your natal chart. Get real-time updates on significant transits and plan important life events with astrological timing.
- Real-time planetary positions
- Transit-to-natal aspect grid
- Upcoming significant transits
Frequently Asked Questions
What is a birth chart calculator?
A birth chart calculator (also called a natal chart generator) creates a map of the sky at the exact moment and location of your birth. It shows the positions of the Sun, Moon, planets, and other celestial bodies in the zodiac signs and houses, providing insights into your personality, strengths, and life path.
How accurate are online astrology calculators?
Zodisphere's calculators use the Swiss Ephemeris and astronomy-engine library for precise astronomical calculations. Accuracy depends on having your exact birth time and location. With accurate birth data, planetary positions are calculated to within arc-seconds of precision.
What is the difference between Western and Vedic astrology?
Western astrology uses the tropical zodiac, which aligns with the seasons and equinoxes. Vedic astrology (Jyotish) uses the sidereal zodiac, aligned with actual star constellations. Due to precession, there is approximately a 24-degree difference between the two systems, which can place planets in different signs.
What is a synastry chart used for?
A synastry chart compares two birth charts to analyze relationship compatibility. It examines how the planets in one person's chart aspect the planets in another's, revealing areas of harmony, attraction, and potential challenges between partners.
What is BaZi (Four Pillars of Destiny)?
BaZi, or Four Pillars of Destiny, is a Chinese astrological system that uses your birth year, month, day, and hour to create four 'pillars' of Heavenly Stems and Earthly Branches. It analyzes the balance of five elements to provide insights into personality, relationships, career, and life cycles.