Surya Siddhanta vs Drik Siddhanta — what is the difference?
Surya Siddhanta computes planetary positions from the mean-motion tables of the classical Sanskrit text of the same name; Drik Siddhanta ("drik" = seen) computes them from modern observational astronomy, so its positions match where a telescope actually finds the planet today. Both are legitimate Vedic methods — Surya Siddhanta preserves the parampara a lineage was taught in, Drik Siddhanta preserves observational truth.
Written and reviewed by the team that builds the Jyotish Sarathi calculation engine.
Key takeaways
- Surya Siddhanta = classical algorithm, fixed mean motions, unchanged for centuries.
- Drik Siddhanta = modern computed astronomy (in Jyotish Sarathi, the Swiss Ephemeris), matching observed sky positions.
- The two can disagree by a degree or more on some planets — enough to change a nakshatra pada or a dasha start date in a borderline chart.
- Neither is "wrong". Use the one your lineage or your client's panchanga uses, and be consistent.
- Jyotish Sarathi computes both and lets you switch between them, so you can see the same chart under each method.
What Surya Siddhanta actually is
The Surya Siddhanta is one of the classical siddhanta texts of Indian astronomy. It gives each planet a mean daily motion and a set of correction steps (manda and shighra corrections, roughly analogous to correcting for an elliptical orbit and for the Earth–Sun geometry) that turn that mean motion into a true longitude for a given day.
Because the constants were fixed when the text was compiled, the algorithm is completely deterministic and reproducible. That is exactly why traditional panchanga-makers value it: two astrologers a century apart, following the same text, get the same number. Nothing depends on a modern data file.
The trade-off is drift. The sidereal year the text uses is slightly longer than the astronomically measured year, and the mean motions carry small errors. Over centuries those small errors accumulate, so a Surya Siddhanta longitude for today is not quite where a telescope points.
What Drik Siddhanta actually is
Drik means "seen" or "observed". Drik Siddhanta (also written Drig or Drk Siddhanta) means: compute the planet where it is actually observed to be. In practice that means using a modern high-precision ephemeris rather than classical tables.
Jyotish Sarathi uses the Swiss Ephemeris for Drik Siddhanta positions — the same numerically-integrated ephemeris lineage used by professional astronomy software. Sidereal (nirayana) longitudes are then derived by subtracting the ayanamsha you have selected from the tropical longitude.
How far apart do the two charts land?
For most charts the rashi (sign) placements of the planets agree. The disagreements show up in the details that depend on exact degrees:
| What you are reading | Sensitivity to the method |
|---|---|
| Rashi of a planet | Rarely changes — only if the planet sits within about a degree of a sign boundary |
| Nakshatra and pada | Can change — a pada is 3°20′, so a 1–2° shift matters |
| Vimshottari dasha balance at birth | Changes — dasha balance is computed from the Moon's exact position in its nakshatra |
| Bhava (house) cusps | Depends mostly on birth time and ayanamsha rather than the siddhanta |
| Gochar (transit) dates | Shifts by days for slow planets |
| Outer planets | Available in Drik Siddhanta only |
The practical rule: if your reading hangs on a nakshatra pada, a dasha start date, or a close transit, the method you chose is part of the answer, and you should say which one you used.
Which one should you use?
- Follow your parampara. If you were taught from a Surya Siddhanta panchanga, or your guru's readings are built on it, staying consistent matters more than switching to the more "accurate" number.
- Match the panchanga your client lives by. In Nepal, a good deal of published patro and muhurta material is traditional. A chart that disagrees with the client's wall calendar creates doubt whether or not you are right.
- Prefer Drik Siddhanta for observational work. Eclipses, exact transits, precise muhurta timing and anything you want to verify against the actual sky belong in Drik mode.
- Prefer Drik Siddhanta if you need the outer planets or a KP-style analysis that depends on fine sub-divisions.
- Never mix them inside one reading. Casting the natal chart in one method and the transits in the other quietly introduces an error you cannot see.
Seeing both for the same chart
The fastest way to build an intuition for this is to cast one chart twice. In Jyotish Sarathi, open the siddhanta setting, generate the kundali, switch the method and generate again — then compare the nakshatra padas and the dasha balance. On most charts you will see the signs hold and the fine detail move.
Both methods are computed on the device, offline, over an ephemeris range of 1768–2293 AD. See the calculation methodology for exactly how each is derived, or the dual siddhanta feature page for what the setting does in the app.
Frequently asked questions
Is Drik Siddhanta more accurate than Surya Siddhanta?
Astronomically, yes — Drik Siddhanta positions match observed planetary positions, while Surya Siddhanta positions drift because its constants were fixed centuries ago. Traditionally, "accuracy" also means agreement with the parampara and the panchanga a reading is based on, and by that standard Surya Siddhanta is the correct choice for many astrologers.
Which siddhanta does Jyotish Sarathi use by default?
Both are available and you choose in settings. Drik Siddhanta positions come from the Swiss Ephemeris; Surya Siddhanta follows the classical mean-motion algorithm. You can switch at any time and regenerate the same chart under either method.
Does the ayanamsha choice matter more than the siddhanta choice?
Often yes. Ayanamsha values differ from each other by more than the two siddhantas typically differ, so switching from Lahiri to Raman usually moves a chart more than switching computation methods. See the guide to ayanamsha for the comparison.
Can I see Uranus, Neptune and Pluto in Surya Siddhanta mode?
No. The classical text has no mean-motion tables for planets discovered after it was written, so the outer planets appear only in Drik Siddhanta mode.
In the app
Related guides
- What is ayanamsha, and which one should you use?Ayanamsha is the offset between the tropical and sidereal zodiacs. What it is, why it grows every year, and how Lahiri, Raman and Krishnamurti differ.
- How to choose Vedic astrology softwareNine criteria for judging any kundali program: ephemeris source, siddhanta and ayanamsha visibility, offline use, chart depth, export, privacy and price.