Mangal Dosha calculators give different results because of three well-documented differences — ayanamsa choice, whether the 2nd house is counted as a trigger, and birth-time/timezone handling — most of which reflect genuine, longstanding differences in classical convention rather than one calculator being wrong.
Why does ayanamsa choice cause different results?
Ayanamsa choice matters because the sidereal zodiac is defined as an offset from the tropical one, and the systems in use disagree about the size of that offset.
The three you will encounter are Lahiri (used here, and the standard adopted by India’s Calendar Reform Committee), Raman, and KP (Krishnamurti Paddhati). They differ by roughly half a degree to just over a degree. That is usually too small to change a sign placement — but near a sign boundary it is decisive, which is exactly where results diverge. See our methodology for why Lahiri is used here specifically.
Why does the 2nd house cause different results?
The 2nd house is the single biggest source of genuinely different Manglik and Non-Manglik results. It is the one trigger house the traditions do not agree on.
The 1st, 4th, 7th, 8th and 12th houses are cited consistently across nearly all classical sources. The 2nd is a real point of disagreement: South Indian tradition and several regional texts include it, while other schools do not. A chart with Mars only in the 2nd house can therefore come back Manglik on one site and Non-Manglik on another, with both calculating correctly according to the convention they follow.
This site includes the 2nd house and flags it explicitly whenever it is the deciding factor, so you can see when your result depends on a convention rather than on a rule everyone shares.
Which tradition is correct about the 2nd house?
Neither, in the sense that this is a genuine disagreement rather than an error. South Indian practice counts the 2nd house as standard; the most widely reproduced classical verse lists the 1st, 4th, 7th, 8th and 12th and omits it. We include it and disclose that we do.
How can you tell which convention a calculator uses?
Usually you cannot, which is the real problem. Most sites publish a verdict without publishing a method. If a calculator does not tell you whether it counts the 2nd house, which reference points it uses, and how it handles cancellation, its disagreement with another calculator is uninterpretable.
Why does birth-time and timezone handling cause different results?
Birth-time and timezone handling is less a convention difference and more a genuine accuracy question — a calculator that mishandles historical timezone rules, daylight saving time, or coordinate-based local time can shift the Ascendant enough to change the result, particularly near a sign boundary.
What does this site do to reduce these differences?
Three choices, one for each source of divergence above.
Whole-sign houses and the Lahiri ayanamsa are used because they are the most widely used conventions in mainstream Indian astrology software and match India’s official Panchang standard. The 2nd house is checked, but flagged explicitly whenever it is the deciding factor, so a convention-dependent result never looks like a settled one. And a timezone database covering roughly 160 cities is maintained specifically to reduce the third source of error.
The point of naming all three is that any disagreement between this site and another should trace back to one of them. If it does not, that is worth reporting — it would mean one of the two calculations is simply wrong.
Where is our own position documented?
Our methodology states which conventions we use and why — the 2nd house, the three reference points, the cancellation handling, and the four classical factors we deliberately do not score.
The 2nd house covers the single largest source of disagreement, and the ten cancellation rules covers the second largest.
Frequently asked questions
Can two correct calculators disagree? Yes. That is the central point of this page: different conventions produce different verdicts without either being wrong.
If two calculators disagree, which one is right? Often both are calculating correctly, making different, defensible choices about ayanamsa or the 2nd-house convention.
Which cause of disagreement is most common? The 2nd house. It is the one trigger house traditions genuinely dispute, so including or excluding it changes the verdict on a large share of charts.
Which calculator should I trust? One that publishes its method. A verdict without a stated method cannot be checked, whatever number it produces.
Do you count the 2nd house? Yes, and every result states when the 2nd house is your only trigger — because your reading would change under a tradition that excludes it.
Why does my 2nd house Mars show as Manglik on one site and not another? Because the 2nd house is a genuine point of disagreement between classical traditions, not a universally agreed trigger.
Does ayanamsa choice change the result? It can, near a sign boundary. Different ayanamsa values shift every position by a fraction of a degree, which only matters when a body sits within about half a degree of a cusp. We use Lahiri and say so.
Is one calculator more correct than another? Not necessarily. Two calculators can be internally consistent and still disagree because they follow different traditions. What separates a good one from a bad one is whether it tells you which choices it made.
Where to go next
our methodology documents the calculation in full — ephemeris, ayanamsa, house system, the ten rules and the scoring decisions that are ours rather than classical. why calculators disagree explains why another site may disagree with us, and what the evidence supports separates what is astronomically verifiable here from what is traditional interpretation.