EstreviaOpen App
Sidereal · Lahiri · Swiss Ephemeris

Your True
Zodiac Sign

Western astrology froze the zodiac to the seasons in 100 AD. The sky has shifted 24° since then. Sidereal astrology tracks the actual constellations — most people discover their Sun is in a different sign entirely.

No account needed · Calculation takes under 2 seconds

How it works

From birth data to shareable card in under a minute.

  1. 01

    Enter birth data

    Date and birth city. Time is optional — without it you still get planetary signs.

  2. 02

    See your chart

    Sidereal positions calculated via Swiss Ephemeris, corrected for Lahiri ayanamsa.

  3. 03

    Share your Passport

    Generate a Cosmic Passport card with your Sun, Moon, ASC — shareable in one tap.

Everything in one place

  • Natal Chart

    Full sidereal natal chart with 12 celestial bodies, Placidus houses, aspects, and degree positions. Swiss Ephemeris precision.

  • Moon Phases

    Live moon phase with illumination percentage, ingress times, and a 30-day calendar. See exact New and Full Moon moments.

  • Planetary Hours

    Classical Chaldean planetary hours for your location. Know which planet governs the current hour and plan accordingly.

  • 777 Correspondences

    Crowley's 777 — colors, gems, incense, deities, Kabbalistic paths — mapped to every planet and sign. Pre-1929 texts, public domain.

  • Check Compatibility

    Compare two natal charts and discover the hidden dynamics between you and another person. Sidereal synastry reveals emotional, intellectual, and karmic connections.

    Try Synastry

  • Thoth Tarot

    78 cards of the Thoth deck with esoteric correspondences, Hebrew letters, and Tree of Life paths. Draw a daily card or explore the full catalog.

    Explore Tarot

  • Explore the Tree of Life

    Navigate the Kabbalistic Tree of Life with interactive Sephiroth, 22 paths, and Crowley's 777 correspondences mapped to planets and signs.

    View the Tree

Join astrologers discovering their sidereal signs

Most discover they carry the energy of the sign before their tropical Sun — not the one on their horoscope app.

±0.01°Calculation accuracySwiss Ephemeris
12Celestial bodiesSun → Chiron
120Esoteric essays10 planets × 12 signs

Common questions

What is the difference between sidereal and tropical astrology?
Tropical astrology fixes the zodiac to the equinoxes — the Sun enters Aries on the spring equinox. Sidereal astrology aligns the zodiac to the actual star constellations. Due to the precession of the equinoxes (~50″ per year), the two systems are currently ~24° apart. Most people in sidereal astrology find their Sun is in the sign before their tropical one.
What is the Lahiri ayanamsa?
The ayanamsa is the angular offset between tropical and sidereal zodiacs. Lahiri (also called Chitrapaksha) is the official ayanamsa adopted by the Indian government and the most widely used in Vedic/Jyotish astrology. As of 2026 it is approximately 24°7′.
How accurate are the calculations?
Estrevia uses Swiss Ephemeris — the same engine used by Solar Fire and Astro.com — with ±0.01° accuracy for all 12 celestial bodies. Over 100 reference charts are verified in CI against Astro.com before every release.
What is a Cosmic Passport?
A shareable card with your sidereal Sun, Moon, and Ascendant signs, dominant element, and combination rarity percentage. Share it as an image or link — works without creating an account.

Early access

Get notified when we launch

Full natal chart calculation, 120 sidereal essays, Cosmic Passport, and planetary hours — all free at launch.

No spam. Unsubscribe at any time.

Calculate My Sidereal Chart