॥ श्री पराशराय नमः ॥

Transparency · Trust

Why do kundli apps disagree?

Same birth date, same time, same city — yet one app says your Lagna is Simha and another says Kanya. Nobody is necessarily lying. Here are the five real reasons, ranked by how much they actually matter.

1. Birth-time uncertainty

The Lagna changes roughly every two hours, and near a sign boundary even 5–10 minutes flips it. Hospital clocks round, memories drift. If your time is approximate, every Lagna-based result — houses, dasha balance, yogas — carries that uncertainty. This is the #1 cause of disagreement and the only one that is about your data, not the app.

Highest impact

2. Ayanamsa choice

Vedic astrology subtracts the ayanamsa (~24°) from tropical positions — but there are several ayanamsas (Lahiri, Raman, Krishnamurti…) differing by up to ~1.5°. Near a sign or nakshatra boundary, that flips placements. We use Lahiri, the official Indian standard — and we say so on every page.

Medium impact

3. House system

Most Indian apps use whole-sign houses (each sign = one house from the Lagna). Some use Sripati/Bhava Chalit, which can shift planets near cusps into neighbouring houses. Both are classical; they just answer slightly different questions. We show whole-sign by default with a Bhava Chalit toggle.

Medium impact

4. Ephemeris accuracy

Cheap apps use low-precision formulas; ours is validated against NASA JPL ephemerides to a fraction of an arc-minute. In practice this rarely flips a sign — but near boundaries, precision is the difference between right and wrong.

Low impact, usually

5. Interpretation traditions

Even with identical charts, predictions differ because dasha systems (Vimshottari vs Yogini vs Chara), dosha definitions (is Kaal Sarp even classical?), and remedy traditions vary by region and lineage. We document our classical sources for every computation — and mark our own syntheses as such.

Medium impact

What to do about it

If two apps disagree on your Lagna or nakshatra, suspect birth-time uncertainty first — try our Birth Time Lab. If they agree on the chart but differ on predictions, that's tradition, not error — read our methodology page to see exactly which texts each of our computations follows. And if an app won't tell you its ayanamsa or sources at all — that's your answer about that app.

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