how to read a birth chart and its houses
A birth chart is a snapshot of the sky at the exact moment of birth: the position of every planet on the ecliptic, plus the houses that split that snapshot into 12 sectors tied to the local horizon and meridian. This page explains the calculation mechanism, not the symbolic meaning, which lives in the tool itself.
The difference comes from São Paulo's latitude (23.55° south): Placidus compresses or stretches houses to match the sky's real tilt at that location, while Equal Houses simply adds 30° to the Ascendant repeatedly, ignoring latitude altogether.
No planet moved: only the house ruler changed system, and that alone was enough to shift the Sun from "philosophy and travel" (house 9) to "career" (house 10) in the traditional reading.
The engine tests five major aspects (conjunction, sextile, square, trine, opposition) within orbs of 4° to 8°; an orb of 0.18° is a near-exact aspect, the kind of genuine astronomical coincidence that only shows up with real ephemerides.
It is the portrait of the Sun, Moon, planets and points (ascendant, Midheaven) at the moment and place of your birth, distributed across the 12 signs and 12 houses. Each body represents a psychic function (the Sun is identity, the Moon emotions, Mercury the mind, and so on); the sign shows the "how" and the house shows "where" in life that energy plays out.
Because the Ascendant and house cusps depend on local sidereal time, which advances about 1° every 4 minutes; without an accurate time, the Sun and planets still land in the right sign, but the Ascendant, Midheaven and each planet's house can no longer be calculated with precision.
Placidus by default, the system most used in modern Western astrology, which splits quadrants by day and night semi-arc through an iterative calculation; above 66° latitude, where that method breaks down, the engine automatically switches to Equal Houses.
It is the angle between two planets on the ecliptic: conjunction (0°), sextile (60°), square (90°), trine (120°) and opposition (180°) are the five major aspects, each accepted within a margin (orb) of 4° to 8° before it stops counting.
No: the birth chart calculates real astronomical positions for a specific instant and place, while a daily horoscope is text generated from a deterministic seed based on sign and date, without running any ephemeris at all; the two deserve different treatment.
Without a time, the rising sign and houses are imprecise. Sun, Moon and planets stay valid (we use noon).
Fill in date, time and city and generate your full birth chart.
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