Birth Chart Calculator

A birth chart (or natal chart) is a snapshot of the sky at the exact moment you were born. It maps the positions of the Sun, Moon, planets, and astrological houses from your specific birthplace and time, and is the foundation of every personalized astrology reading.

Yes — completely free, no signup, no email required. Calculate as many charts as you want for yourself, family, friends, or relationship synastry.

This calculator uses Swiss Ephemeris-backed planetary positions and the project accuracy contract: planet longitudes, Rising sign, and Midheaven within ±0.5°, and Placidus house cusps within ±1° when given an exact birth time.

For Sun and Moon signs, no — date alone is enough. For Rising sign and house placements, yes — birth time matters down to the minute. The Ascendant shifts about one degree every 4 minutes, so a one-hour estimate can change your Rising sign entirely.

Your chart shows the sign and house of all 10 classical planets (Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto), your Ascendant (Rising sign) and Midheaven, the 12 house cusps, and major aspects (conjunctions, oppositions, trines, squares, sextiles) showing how your planets interact.

The public calculator presents Placidus houses, the most common system in Western astrology. The calculation library also supports whole-sign houses for specialized surfaces, but Placidus cusps use the project's pure TypeScript Meeus implementation.

They are the same thing. "Birth chart" and "natal chart" are interchangeable terms for the snapshot of the sky at the moment of your birth. Some astrologers prefer "natal" for technical contexts, "birth" for general use.