Nakshatra Boundaries and Moon Rashi

“What is my nakshatra?” sounds like a name lookup, but the name follows a specific sky position. A birth date alone can be ambiguous because the Moon moves through the zodiac during a civil day. This guide explains the mathematics behind the Janma Nakshatra lookup: the local timestamp is converted to UTC, the Moon’s apparent geocentric longitude is calculated, and an approximate Lahiri offset yields a sidereal longitude.

Twenty-seven equal Moon ranges

This calculation divides the full 360° zodiac into 27 consecutive spans of 13°20′, beginning at sidereal Aries 0°. The range starts are inclusive and the ends lead into the next range. Nakshatra names have multiple English transliterations; the spelling below is used consistently in this site’s birth-chart and Moon lookup tools. The ranges are longitude intervals, not measured widths of the physical star groups bearing these names.

How to find the pada

Each 13°20′ nakshatra contains four padas of 3°20′. Subtract the start of the nakshatra from the Moon’s sidereal longitude. The first 3°20′ inside it is pada 1; the next is pada 2; the third is pada 3; and the last is pada 4. At exactly a boundary, this calculator assigns the Moon to the new pada or nakshatra beginning there. Displayed one-decimal-degree positions are truncated for readability, while the assignment uses the unrounded longitude.

Worked boundary examples

A sidereal Moon at 0°00′ Aries is at the start of Ashwini, pada 1, with Aries as its Moon rashi. At 3°20′ Aries it has entered Ashwini pada 2. At 13°20′ Aries it has entered Bharani pada 1. At 29°59′ Pisces it is in Revati’s final pada, while 0°00′ Aries begins the sequence again. A Moon around 16.7° Libra, as in the calculator’s 1 January 2000 noon Delhi example under its approximation, is in Swati pada 4. Its rashi is Libra; those two names refer to different sized intervals.

What if the birth time is unknown?

Choose the unknown-time option to calculate the Moon at local 00:00 and 23:59 for the entered date and fixed UTC offset. The result lists every nakshatra and rashi crossed between those endpoints. If it lists two names, the correct one depends on when the birth occurred. Even when it lists one name for the full sampled day, a different historical time-zone rule or ayanamsha can matter close to the start or end of that range. The lookup does not invent a precise birth pada without a recorded time.

Why sites can disagree

Check the input clock time first, then whether the offset was east or west of UTC and whether historical daylight saving applied. Compare the ayanamsha name, Moon ephemeris, geocentric versus topocentric convention, and whether the other result uses a sunrise-to-sunrise panchanga date. Our Moon lookup reports the birth instant. The separate panchanga calculator reports daily parts at local sunrise as well as a selected instant, so its headline can differ for a birth before sunrise.

The underlying lunar position uses Astronomy Engine’s apparent geocentric ecliptic transform. It does not run the Swiss Ephemeris. A 0.1° notice on the result marks especially close sign, nakshatra, or pada boundaries; other methodological differences can still occur elsewhere. The supported local birth dates are 1800–2100.

The nakshatra overview places the 27 names in their wider historical and symbolic context.

Find your Moon nakshatra →