Free Western Birth Chart Calculator

Everything on the result card is computed, not looked up. The engine takes your date, time and place, converts the civil time to UTC through the IANA time zone (daylight saving included), and asks the Swiss Ephemeris for the tropical longitude and daily speed of the Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto and the true North Node at that instant. With a place it also casts the Ascendant, Midheaven and the twelve Placidus house cusps (Porphyry beyond the polar circles, where Placidus has no solution). Each planet is then placed in its house, checked for retrograde motion and given every traditional dignity it holds — domicile, exaltation, detriment or fall (Mercury in Virgo is both at home and exalted) — and every house cusp is given its ruler, modern and traditional, with the sign and house the ruler sits in.

Chiron and the asteroids are deliberately not shown. The built-in Moshier ephemeris does not carry them, and we would rather show nothing than an approximation.

The Sun sign is the one you already know from horoscopes — the sign the Sun occupied on your birthday, which describes identity, vitality and purpose. The Moon sign changes every two and a half days and describes your emotional reflexes, what you need to feel safe and how you react before you think. The rising sign (Ascendant) is the sign that was climbing over the eastern horizon at the minute you were born; it moves through all twelve signs in a day, which is why the birth time matters so much. It sets the house cusps and describes how you come across to people who have just met you.

If you do not know your birth time, tick the box: the calculator still gives you the Sun and Moon signs and every aspect, but leaves out the rising sign and the houses rather than guessing them. The Moon moves twelve to fifteen degrees in a day, so the specialist is given the range it covered on your birth date: when it changed sign that day both signs are named, and a Moon aspect that does not hold for every birth time is marked as possible only.

Aspects are the angles between planets. The calculator finds conjunctions (0°), oppositions (180°), trines (120°), squares (90°), sextiles (60°) and quincunxes (150°) using modern orbs — eight degrees for a conjunction or opposition, ten when the Sun or Moon is involved, tighter orbs for the angles, only three degrees for the quincunx, and for the North Node, a point rather than a body, just four degrees for a conjunction or opposition and three for a square. Every aspect is listed with its actual orb, the tightest first, marked exact when it is within one degree and flagged when it is out of sign (a dissociate aspect, which works more weakly).

Because the engine knows each planet's daily speed, it can also tell whether an aspect was applying (the faster planet moving toward the exact angle) or separating at birth. Astrologers read an applying aspect as a theme still being worked out in the life and a separating one as something already integrated. Most free chart calculators skip this; ours shows it on every aspect.

When three or more planets form a closed figure the whole chart takes on that shape. The calculator detects a stellium (three or more planets in one sign, at least two of them personal — the Sun, Moon, Mercury, Venus or Mars; three slow planets on their own are shown as a generational cluster, a trait of everyone born in those years), a grand trine (three planets in mutual trine, usually all in one element — a natural talent that can go unused because nothing forces it), a T-square (an opposition with a third planet square to both — the chart's engine, with the apex planet named), a grand cross (four planets in two oppositions, all mutually square) and a yod (two planets in sextile, both quincunx a third). Each pattern is listed with the planets in it and the sign, element, modality or apex that defines it.

A natal chart is fixed; the sky keeps moving. The result card dates every transit Jupiter, Saturn, Uranus, Neptune and Pluto make to your Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Ascendant and Midheaven from six months ago to two years ahead — each exact pass found by scanning the ephemeris, labelled as the first, retrograde or final pass, with the window during which the transit stays within one degree. It also scans for the classic life-cycle transits — the Saturn return around 29 and 58, the Saturn squares and opposition every seven years, the Jupiter return every twelve, the Uranus opposition and Neptune square around 41 and the Pluto square — and reports whether each is active, upcoming or recently past. When a transit is retrograde you will see three exact dates, which is how astrologers time the first pass, the review and the resolution. Inside a reading the Western specialist also gets the eclipses that fall on your natal points, your tropical solar return and your annual profection with its lord of the year.

Progressions are the slow inner clock of the chart: one day after birth stands for one year of life. The calculator progresses the Sun, Moon, Mercury, Venus and Mars to your current age, shows the progressed Moon's sign and house (each sign is roughly a two-and-a-half-year emotional chapter) and the progressed lunar phase (a thirty-year cycle from new Moon to balsamic), and lists, with their exact dates, the contacts that time events: a progressed planet, the progressed Midheaven or Ascendant, or a planet moved by the solar arc, reaching an aspect to a natal planet within one degree. These are the same figures a professional astrologer would compute before a consultation.

Both, for different questions. The tropical zodiac is anchored to the seasons; the sidereal zodiac used in Vedic astrology is anchored to the fixed stars, and the two have drifted about 24 degrees apart, so your tropical Sun sign is often one sign later than your Vedic Moon sign. ProxaAI keeps them strictly separate: this page is tropical, the free kundli is sidereal, and inside a paid reading the Western astrologer and the Vedic astrologer are different specialists whose facts are never blended. If you want both perspectives on one question, add "Western tropical astrology" to your kundli and the Western specialist joins every reading.