Tithi Calculator
A **tithi** is a lunar day — the basic unit of the Vedic calendar, measuring the angular gap between the Moon and Sun in fixed 12° steps. There are 30 tithis in a full lunar month, 15 in each fortnight, and the same 15 names repeat whether the Moon is waxing (Shukla Paksha) or waning (Krishna Paksha). This calculator finds the exact tithi active at your birth moment, its paksha, and its place in the classical five-fold Nanda/Bhadra/Jaya/Rikta/Purna classification, computed with Lahiri ayanamsa.
Ayanamsa: Lahiri (Chitrapaksha) · Houses: Whole Sign · Nodes: Mean
Creator
James WhitfieldReviewers
Sarah Mitchell, M.A. in Cultural Astronomy & Astrology and Marcus Reynolds, Professional Astrologer & Astronomer
Last updated:
What Is a Tithi?
A tithi is defined purely by angle, not by the clock: it's the time it takes the Moon to gain 12° of angular distance ahead of the Sun. Because the Moon's speed varies slightly through its orbit, a tithi's real-world length varies too — usually somewhere between about 19 and 26 hours — which is why a tithi rarely lines up neatly with a calendar day and can even be skipped or repeated across two sunrises.
A full synodic month (new moon to new moon) contains exactly 30 tithis, split into two fortnights (pakshas) of 15 each. The tithi active at any given moment — including the moment of birth — is one of the five limbs (panchang) used in traditional Vedic timekeeping, alongside vara (weekday), nakshatra, yoga and karana.
Shukla vs. Krishna Paksha
A lunar month splits into two pakshas (fortnights): Shukla Paksha, the waxing fortnight from new moon to full moon, and Krishna Paksha, the waning fortnight from full moon back to new moon. Both fortnights use the exact same 15 tithi names, in the same order, starting from Pratipada — the paksha tells you whether the Moon is growing or shrinking, while the tithi name tells you how far along that fortnight you are.
The only difference at the very end of each fortnight is the name of the 15th tithi: it is called Purnima (full moon) at the close of Shukla Paksha, and Amavasya (new moon) at the close of Krishna Paksha. Both mark a fortnight's completion, and both carry real significance in the calendar, but they are treated as distinct occasions rather than interchangeable.
The Five Tithi Groups (Nanda, Bhadra, Jaya, Rikta, Purna)
Classical Jyotisha sorts the 15 tithi names into five recurring groups of three, a well-documented traditional classification used to judge a tithi's general suitability for different kinds of activity:
| Group | Tithis | General character |
|---|---|---|
| Nanda | Pratipada, Shashthi, Ekadashi | Joyful, energetic — good for fresh starts and celebration |
| Bhadra | Dwitiya, Saptami, Dwadashi | Stable, auspicious — good for commitments meant to last |
| Jaya | Tritiya, Ashtami, Trayodashi | Victorious — good for effort that must overcome resistance |
| Rikta | Chaturthi, Navami, Chaturdashi | Empty — generally avoided for new beginnings |
| Purna | Panchami, Dashami, Purnima | Complete, fulfilling — good for bringing things to conclusion |
Amavasya (new moon) sits outside this five-fold pattern as its own special case — it marks the lunar cycle's end and is generally treated with Purna-like significance around completion, while also carrying its own distinct observances in different traditions. This grouping is one voice among several a muhurta calculation weighs, not an absolute rule on its own.
Tithi in Muhurta
Muhurta is the classical practice of choosing an auspicious moment for an important activity — a wedding, a business launch, laying a foundation — and the tithi active at that moment is one of its central inputs. A Rikta tithi, for instance, is generally avoided for starting something new, while a Bhadra or Purna tithi is more often favored for undertakings meant to endure or conclude well.
Tithi is never read alone in serious muhurta work — it is combined with the vara (weekday), nakshatra, yoga and karana active at the same moment, along with planetary positions, to judge a window's overall quality. Knowing your birth tithi is also useful outside muhurta, since certain observances (like Ekadashi fasting) are tracked by tithi rather than by calendar date.
Tithi Calculator FAQs
What is a tithi, exactly?
How is a tithi different from a calendar date?
What is the difference between Shukla and Krishna Paksha?
What are the five tithi groups (Nanda, Bhadra, Jaya, Rikta, Purna)?
Is Ekadashi special compared to other tithis?
Why does my tithi matter if I only care about my birth chart?
Can two people born a few hours apart have different tithis?
Does tithi depend on birth time the way Lagna does?
Related Birth & Kundli Calculators
Vedic Birth Chart Calculator
Full sidereal birth chart — Lagna, Rashi, all nine grahas, whole-sign houses, Vimshottari dasha, and the yogas in your kundli.
Kundli Calculator
Generates your full Vedic kundli — planetary positions, houses, and dasha periods — from birth date, time, and place.
Lagna Calculator
Computes your Lagna (ascendant) sign — the zodiac rising on the eastern horizon at the moment of birth.
Rashi Calculator
Finds your Moon sign (Rashi) — the sidereal zodiac sign the Moon occupied at your birth.
Ascendant Calculator
Calculates your rising sign and exact ascendant degree from birth time and place using sidereal astrology.
Nakshatra Calculator
Identifies your birth Nakshatra — the lunar mansion the Moon was transiting at birth — from among the 27 nakshatras.
Nakshatra Pada Calculator
Pinpoints your Nakshatra Pada — the quarter (1–4) of your birth nakshatra — for navamsa and remedial calculations.
Birth Star Calculator
Determines your birth star (Janma Nakshatra) and its ruling deity, planet, and symbol from your exact birth time.
Yoga Calculator
Finds the panchang Yoga in effect at birth — one of the 27 Sun-Moon angular combinations used in muhurta and prediction.
Karana Calculator
Determines the Karana — half-tithi period — active at your birth, one of the 11 karanas used in panchang analysis.