"Panchaka" literally means "a group of five" — but in muhurta context it is the name for a numerical test that combines five sources of stellar / zodiacal energy and classifies the moment into one of six categories. A slot whose result lands outside the five inauspicious flavours is called Panchaka Rahitam — "free of panchaka" — and is the safe baseline window for most ceremonies.
The classical formula
Per B. V. Raman's Muhurtha, panchaka is determined by adding four numbered factors and taking the remainder modulo 9:
remainder = (Tithi # + Weekday # + Nakshatra # + Lagna #) mod 9
Number each factor as follows:
- Tithi # — counted 1…15 within each paksha (Pratipada = 1, Dwitiya = 2, …, Purnima or Amavasya = 15). Same number for Shukla and Krishna paksha.
- Weekday # — Sunday = 1, Monday = 2, Tuesday = 3, Wednesday = 4, Thursday = 5, Friday = 6, Saturday = 7.
- Nakshatra # — Ashwini = 1, Bharani = 2, …, Revati = 27.
- Lagna # — ascending rashi at the muhurta moment: Aries = 1, Taurus = 2, …, Pisces = 12.
Remainder → category
- Remainder 1 — Mrityu Panchaka (death panchaka). Severe; avoid.
- Remainder 2 — Agni Panchaka (fire). Avoid for fire / yajna / electrical / kitchen work.
- Remainder 3 — Panchaka Rahitam ✓
- Remainder 4 — Raja Panchaka (bad results). Avoid for occupational / business starts.
- Remainder 5 — Panchaka Rahitam ✓
- Remainder 6 — Chora Panchaka (theft). Avoid travel, carrying valuables.
- Remainder 7 — Panchaka Rahitam ✓
- Remainder 8 — Roga Panchaka (disease). Avoid for marriage, upanayanam, medical starts.
- Remainder 0 — Panchaka Rahitam ✓
Worked example
Anuradha nakshatra, Panchami tithi, Wednesday, Scorpio lagna:
17 (Anuradha) + 5 (Panchami) + 4 (Wednesday) + 8 (Scorpio) = 34
34 mod 9 = 7 → Panchaka Rahitam
Per-event exceptions
Not every panchaka blocks every event. The classical rule is: each event-type has a specific panchaka to avoid, and other panchakas can be ignored if a Rahitam slot cannot be secured:
- Occupation / business starts — avoid Raja Panchaka.
- House building / construction — avoid Raja and Agni Panchaka.
- Travel / journeys — avoid Chora Panchaka.
- Marriage and upanayanam — avoid Roga and Mrityu Panchaka.
So a slot tagged Chora Panchaka is acceptable for marriage but not for travel; a slot tagged Raja Panchaka can be used for travel or marriage but not for opening a business. Where any Rahitam slot exists, prefer it; the exception list is a "lesser-evil" fallback.
How the filter works
Every slot in the calculator is labelled with one of the six categories above (computed at the slot's tithi, weekday, nakshatra, and rising sign). The default Panchaka filter accepts every slot. To tighten:
- Routine ceremonies (house-warming, naming, business opening, marriage rituals) — select only Panchaka Rahitam.
- Marriage / upanayanam — deselect Roga and Mrityu; the rest are fine if Rahitam is unavailable.
- Travel — deselect Chora.
- Business / occupation — deselect Raja.
- House construction — deselect Raja and Agni.
Because panchaka depends on four moving factors, the category can flip several times in a day as tithi, nakshatra, or lagna change. The calculator recomputes it for every slot (15-minute resolution by default), so you may see Rahitam in the morning and Mrityu in the afternoon for the same calendar date.