Astrologer Birth Charts

The natal chart is the centre of the workspace: an interactive wheel with planets, signs, houses, angles, and aspect lines you can click placement by placement. Positions come from the Swiss Ephemeris, so they match the published ephemerides working astrologers already check against.

How Astrologer calculates a birth chart

Astrologer computes planetary positions with the Swiss Ephemeris, the same JPL-derived engine the established professional desktop suites are validated against. Positions are accurate to ±0.001 arcseconds over a range from 5400 BCE to 5400 CE, which means historical charts and far-future progressions stay reliable rather than degrading at the edges. Time zones are resolved from the birth location against the historical zone database, so a chart cast for a 1940s wartime birth or a half-hour zone gets the offset that was actually in force on that date rather than the one in force today. This matters more than it sounds: an incorrect historical DST offset moves the Ascendant by a full sign surprisingly often.

House systems and zodiacs

Astrologer supports 12 house systems — Placidus, Whole Sign, Equal, Vehlow, Koch, Porphyry, Regiomontanus, Campanus, Topocentric, Alcabitius, Meridian, and Morinus — switchable per chart without recasting from scratch. Both tropical and sidereal zodiacs are available, including the Lahiri and Fagan-Bradley ayanamsas. Because house system is a per-chart setting rather than a global preference, you can keep a Whole Sign chart open beside a Placidus one and compare how the same placements redistribute.

What you can read on the wheel

The wheel is interactive rather than a static image: click any planet to see its sign, house, degree, dignity, and every aspect it makes with orbs. A full aspect grid shows every major and minor angle between bodies. Essential dignity scoring weighs rulership, exaltation, detriment, and fall so you can judge how well-placed each planet actually is. Beyond the traditional seven you can plot asteroids, centaurs, fixed stars, Arabic parts, midpoints, and declinations including out-of-bounds flags. Charts export as high-resolution PNG or PDF for clients and study.

Interpretation attached to the chart

Every placement carries a plain-English reading written for that specific combination — not a generic sign description pasted under a glyph. The interpretation corpus covers planet-in-sign, planet-in-house, and every planet-pair aspect, and it describes how a configuration works rather than telling you what to do about it. That is a deliberate editorial rule: the text explains the mechanism and stops there.

Frequently asked questions

Other Astrologer capabilities