Ayanamsa
Glossary · Last updated: 2026-07-26
Ayanamsa (from Sanskrit ayana + amsha) is the difference between the tropical and sidereal zodiac origins, expressed in degrees.
Pick a different ayanamsa and your sidereal Moon or Lagna can land in an adjacent sign near boundaries. Lahiri is our default.
Example: see it on a birth date
Ayanamsa is the size of the tropical-to-sidereal gap. We use Lahiri. On April 20, 2021 the Indian Vedic Moon estimate is Karka rashi.
A different ayanamsa can move a result that sits near a sign boundary. This page names the gap. It does not pick a gemstone or a prediction.
Enter your own date on the Zodiac Sign Calculator.
Schools differ slightly
Raman, Krishnamurti, and other ayanamsas exist. For educational apps, using one system consistently matters more than debating which school is the authority.
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.