Western (Hellenistic → Modern)
The tropical system most of the world knows: sun/moon/rising, aspects, and transits, traced from its Hellenistic roots to the modern chart.
Tropical · Tropical zodiac, Placidus/whole-sign houses, aspects
How the math differs
The Western system is tropical: 0° Aries is pinned to the northern vernal equinox, so the zodiac is defined by the Sun–Earth geometry rather than the fixed stars. No ayanamsa is applied.
Houses are usually resolved with a time-based division such as Placidus (or whole-sign), which needs an exact birth time and latitude — the ascendant and midheaven come straight from sidereal time and the local horizon.
Relationships between planets are measured as Ptolemaic aspects — conjunction, sextile, square, trine, opposition — each with an orb, so an aspect is a precise angular separation, not a vibe.
What you can compute
Tropical natal chart
Planets and points against the equinox-based zodiac
Placidus / whole-sign houses
Cusps from sidereal time, latitude and birth moment
Ascendant & midheaven
Exact rising degree and MC from the local horizon
Aspect grid with orbs
Ptolemaic angles measured and tolerance-checked
Compute your chart in the Western system
Enter your birth details and get real positions by this tradition’s own rules — free, no sign-up, and nothing leaves your device.