Sidereal vs tropical
Glossary · Last updated: 2026-07-26
The tropical zodiac (Western sun signs) starts Aries at the March equinox. The sidereal zodiac (Indian Vedic) lines up with star backgrounds. It uses an ayanamsa correction.
Neither is 'wrong' by itself. They answer different historical questions. Comparing them side by side is for learning.
Example: see it on a birth date
On July 22, 2020 the Western tropical sun sign is Cancer. The Indian Vedic sidereal Moon estimate is Karka rashi.
Tropical signs follow the seasons. Sidereal signs follow the stars. The two labels answer different questions.
Enter your own date on the Zodiac Sign Calculator.
On this site
Western cards use tropical sun signs. Indian Vedic Moon and Lagna use sidereal positions. Chinese, Mayan, Celtic, Akan, and Tibetan cards use other calendars.
Related
Main reading and tools
These are the main reading and calculator pages. Use them for a daily note, a birth-sign tool, or a pair check.
- Today's Horoscope hubAll twelve Western sun-sign daily pages, plus links to the seven-tradition reader.
- Horoscope & Zodiac CompatibilityTwo birth dates for Western, Chinese, and Indian Vedic pairing, plus every sun-sign hub.
- Zodiac Sign CalculatorWestern sun sign from birth date, with element, modality, and ruler.
- Rising Sign CalculatorIndian Vedic Lagna estimate when you have birth date, time, and place.
- Moon Sign CalculatorIndian Vedic Janma Rashi and nakshatra when birth time and city are available.