Astrool Tropical Zodiac
The zodiac of Western astrology, anchored to the seasons: 0° Aries is always the March equinox.
Definition
The tropical zodiac divides the Sun's yearly path into twelve 30° signs, starting from the point where the Sun crosses the celestial equator heading north, the March equinox. Because it follows Earth's seasons, the Sun always enters Aries around 20–21 March and Cancer at the June solstice.
Why it drifts from the stars
Earth's axis wobbles slowly (precession), so the equinox point slides backward against the stars by about 1° every 72 years. Two thousand years ago the tropical and star-based zodiacs lined up; today they are about 24° apart. That difference is the ayanamsa.
Tropical vs sidereal
The tropical zodiac describes the Sun's relationship to Earth's seasons; the sidereal zodiac describes its position against the constellations. Western astrology uses tropical, Vedic astrology sidereal. Astrool calculates both.
See it in your own chart
Astrool calculates your full birth chart, not just your sun sign, and writes your daily, weekly and monthly readings against it.
Common questions
Is the tropical zodiac wrong because it does not match the constellations?
No. It never claimed to; it is defined by the seasons, not the stars.
Which zodiac does my horoscope use?
Astrool horoscopes and Western birth charts use the tropical zodiac; the Vedic birth chart uses sidereal.