Ayurdaya: what longevity analysis can and cannot say

Vedic astrology has a named calculation for the length of a life. It is called ayurdaya, from ayus, the duration of a life, and daya, an allotment. The classical texts carry three of them. They read different parts of the same birth chart, they were never reconciled with one another, and run on a single chart they return different answers.

That disagreement is not a gap in the record waiting to be filled in. It is the record. Two careful astrologers working from the same manuscripts, on the same birth details, can reach different answers and both be applying the method correctly, because the texts also disagree about which of the three belongs to which chart.

People ask this question in plain words and without any of that vocabulary. On 7 August 2026 someone typed into AstroMedha's chart chat: do i have a long life span ? at least over 70 yeras? Six other people asked a version of the same thing between 16 July and 23 August 2026, seven separate accounts in all, and one of them wrote: My health and longevity, im having many health issues , will I heal.. Will I live long enough to take care of my baby.

Nobody asking that wants a note on manuscript variants. They want to know whether a number an astrologer gave them, or a number they are frightened of, is worth anything. A specific year is worth nothing. A bracket of several decades is worth very little. The parts of the chart the calculation reads are worth reading closely, for other questions.

What the three methods actually read

Each of the three works by allotting years to the planets and adding them up. What separates them is where the allotment comes from.

Pindayu assigns each of the seven planets a maximum number of years, then gives that planet a fraction of its maximum depending on how far it has travelled between the point in the zodiac where it is exalted, meaning the exact degree at which it is held to be at full strength, and the opposite point where it is debilitated, meaning the degree at which it is held to be weakest. A planet near its strongest degree contributes close to its full allotment. A planet near its weakest contributes close to half. The totals are then cut by a series of reductions: a planet combust, which means close enough to the Sun to be overpowered by it, loses a share, as does a planet in a sign owned by a planet hostile to it, and the rising sign contributes a figure of its own. Pindayu therefore depends on the exact degree of every planet.

Amsayu works from the navamsha, which is one ninth of a sign, three degrees and twenty minutes wide, and the same division that produces the D9 chart read for marriage and for a planet's underlying strength. It counts how many of those divisions each planet has travelled through, converts the count into years, and then reduces it by its own set of rules. Amsayu therefore depends on which three-degree step each planet is standing in, and a planet a few arc-minutes either side of a step boundary produces a different count.

Nisargayu assigns each planet a fixed number of years by its nature and does not adjust for where the planet sits at all. It is the simplest of the three and the least sensitive to the chart, which is both its defence and its weakness: it barely distinguishes one person from another.

The specific year values, and the reduction rules that follow them, differ between manuscripts and between commentaries, and AstroMedha computes none of the three. No year figures appear anywhere on this page for that reason. What can be stated with confidence is the shape of each method and what it takes as its input, because that is what decides how much weight its output can carry.

Where the three disagree, and why it matters more than it sounds

Start with the obvious one. Pindayu reads the exact degree of each planet. Amsayu reads which ninth of a sign each planet occupies. Nisargayu reads neither. Give the three the same chart and you do not have three opinions about one measurement. You have three different measurements.

The second disagreement decides everything after it. The texts do not present the three as alternatives to pick from by taste. They give conditions under which each one applies, and those conditions are themselves read from the chart, generally from the relative strength of the rising sign's ruler, the Sun and the Moon. Lineages differ on how that comparison is made, and therefore on which method wins. So the sequence is: judge which method applies, then apply it. An error in the first step is not a small error, because the second step is a different calculation entirely.

The third is that reductions compound. Each one is a subtraction or a scaling applied to a total that was itself an estimate, and each carries its own conditions about when it fires at all. Two practitioners who agree on the method and agree on the chart can still disagree on whether a given reduction applies to a given planet, and the answer moves when they do.

None of this means the tradition was careless. It means the tradition treated this as the hardest thing in the discipline and left more than one route through it. It does mean that anyone who quotes you a single year, with no mention of which method they used or why they chose it, has skipped the two decisions that matter most.

Alpayu, madhyayu and purnayu: what a bracket says

The output of an ayurdaya calculation is usually not a year. It is one of three brackets: alpayu, a short span; madhyayu, a middle span; and purnayu, a full span. The boundary figures vary by text. The commonly quoted division puts the first boundary near the early thirties and the second near the mid-sixties, with the top of the full bracket running to somewhere between ninety-six and a hundred and twenty depending on which manuscript is followed.

Look at what a bracket that wide can carry. Madhyayu, on the common division, spans about thirty years. Saying that someone falls inside it excludes very little, and the answer shifts by a whole bracket if a single reduction is applied differently. Purnayu runs for another thirty-odd years and its upper bound is itself disputed across manuscripts by about twenty-four years.

There is a further point the brackets are usually presented without. In the classical scheme they describe a span the chart is held to allot, and the texts themselves list circumstances that shorten or lengthen what actually happens. The bracket was never meant to be read as an event on a date, and it is wide enough that two people who fall in the same one may have very little in common.

The calculation runs on a number most people do not have

All three methods need a birth chart. Pindayu and Amsayu need the degrees of the planets, and both of them need the rising sign, because the rising sign fixes which house every planet falls in and the reductions are keyed to houses. The rising sign comes from the birth time, and it moves quickly.

To put a size on that, the AstroMedha engine was run over 100,000 randomly generated birth moments: dates uniform between 1 January 1975 and 31 December 2005, clock times uniform across the full twenty-four hours, birthplaces drawn from ten Indian cities, all Indian Standard Time. Each chart was then recomputed with the birth time shifted by five, fifteen, thirty and sixty minutes in both directions, and four things compared against the original: the rising sign, the rising nakshatra, which is one of the twenty-seven lunar mansions, each thirteen degrees and twenty minutes wide, the navamsha ascendant, and the house the 8th lord falls in.

Read the thirty-minute row again. If the recorded birth time could be half an hour out in either direction, it is a coin flip whether the rising sign in front of you is the right one. Half an hour is not an unusual error on an Indian birth record. It is what you get when a time was written down from memory later that day, or rounded to the nearest half hour, or copied off a clock nobody had checked.

The nakshatra column matters for a separate reason. The rising nakshatra is what several birth-time rectification and strength methods key off, so it is often the thing an astrologer uses to check the birth time itself. At thirty minutes of error it had moved in 99.67% of the charts, which makes it a poor check on a figure that is out by that much.

The navamsha column hits Amsayu directly. A navamsha division is three degrees and twenty minutes wide and the ascendant crosses one in roughly thirteen minutes of clock time, so at fifteen minutes of uncertainty the navamsha ascendant moved in every single one of the 100,000 charts. The planets are slower and hold up better: at five minutes of error, at least one of the seven had changed navamsha division in 3.66% of charts, at thirty minutes 20.75%, at sixty minutes 39.47%. Amsayu's inputs are more stable than the ascendant's, and they are still moving in two charts out of five at an hour of error.

So the honest position is this. A method whose first step is a fine-grained reading of the ascendant is being asked to work from a number that a large share of people cannot supply to the precision it needs. That is not an argument that the method is wrong. It is an argument that the confidence with which its answer usually arrives is not available.

What AstroMedha computes here, and what it will not

AstroMedha computes eighteen divisional charts, which are charts built by cutting each sign into equal parts and reading those parts as a chart of their own: the classical sixteen, D1, D2, D3, D4, D7, D9, D10, D12, D16, D20, D24, D27, D30, D40, D45 and D60, plus D5 and D8. There is no ayurdaya routine in the engine, and that absence is deliberate rather than an item waiting on a roadmap.

The D8 Ashtamsa is on that list, and it is the division most often named in longevity work, so it is worth being exact about what having it changes. It changes where each planet falls in a second wheel. It does not produce a span, a bracket or a year, because none of the three classical methods is implemented and the arithmetic for them is not in the engine at all. A division and a lifespan calculation are different objects, and the first has never implied the second.

The health engine's safety contract states it in one line: it never says anything about lifespan, longevity or death, and the 8th house, which is the ayush or lifespan house in the classical scheme, is deliberately read as pace and recovery instead. The words lifespan, longevity, life expectancy, years left, ayush, maraka, death, dying, fatal and mortality are blocked at word boundary in any text that reaches a reader, and a test suite runs against the generated output rather than against a list of intentions.

The chart chat carries the same rule from the other direction. Asked directly when someone will die or how long they have, it is instructed to give no date, to confirm no fear, to say plainly that longevity is not something to read this way, and to turn toward what genuinely supports health now. A person asking that question is often frightened, and the instruction treats it as a moment that needs care rather than a query that needs an answer.

That is also why there is no signed-in longevity reading waiting behind this page. A gate here would be protecting a number, and the number is one the product does not produce.

If your question comes from something a doctor has said, or from symptoms you are living with now, the person who can answer it has examined you and we have not. Take it to them first, and keep taking it back to them.

What the eighth house is read for instead

The 8th house genuinely is the house the classical scheme assigns to length of life. It is also the house of what recurs, what turns over slowly, what arrives without notice, and what is inherited. AstroMedha reads it for those, and for the rate at which a chart spends and recovers energy, which is a statement about pace rather than about a body.

That matters practically, because much of the fear attached to the 8th house comes from how common its supposedly alarming configurations are. From the same 100,000 charts:

Half of all charts have nothing in the 8th house at all, and a third have a malefic sitting there. A configuration a third of the population carries describes a tendency, not a verdict on one person. If you have been told that a planet in your 8th house is a warning, the first useful fact is that roughly one person in three is carrying the same warning.

The 8th lord's own house is close to evenly spread. Across the 100,000 charts it lands in the 1st most often at 9.15% and in the 10th least often at 7.79%, with every other house sitting between those two. There is no house it avoids and none it strongly favours, which is what you would expect from a placement driven by two independent things: which sign is rising, and where one planet happens to be.

Saturn's part in this

Saturn is the planet the classical scheme makes responsible for length of life, and it is the planet most people are told to worry about. Its aspects fall on the 3rd, the 7th and the 10th houses counted from wherever it sits, a wider reach than most planets have.

Across the 100,000 charts, Saturn's aspect lands on the rising sign in 24.88% of them, on the 8th house in 25.10%, and on one or the other in 41.63%. Two charts in five have Saturn touching one of the two houses a longevity reading leans on hardest. That is a description of how the geometry works out across a population, not a finding about any one person.

What AstroMedha does with Saturn is date things. Saturn's periods and its transits are used to say when a period is likely to ask more of you and what that period tends to be good for, which is a claim you can check against a life you have already lived. A claim about the end of a life cannot be checked by the person it is about, which is one reason it is so easy to make.

One chart, read three ways, with no number at the end

Here is the birth moment AstroMedha uses to draw its public teaching charts: 15 July 1990 at 09:20 in Mumbai. It is a composed moment rather than anybody's real one, and every placement in it is the engine's own output.

The ascendant, or lagna, which is the sign coming up over the eastern horizon at the moment of birth, is Leo at 10.96 degrees, in the nakshatra Magha, fourth quarter. The navamsha ascendant is Cancer, so the ascendant is not vargottama, which would mean holding the same sign in both charts. The 1st house is empty and no planet aspects it.

The 8th house is Pisces. Its lord is Jupiter, and Jupiter sits in Gemini at 28.74 degrees, in the 11th house, combust at a separation of 0.1 degrees from the Sun against an eleven-degree orb, which is about as deeply combust as a planet gets. In the D9 it holds Gemini again, so it is vargottama there. The Moon occupies the 8th house in Revati, and Ketu aspects the house.

Saturn is in Sagittarius in the 5th house, retrograde, meaning apparently moving backwards against the stars as seen from Earth, in Uttara Ashadha. Its three aspects fall on the 7th, the 11th and the 2nd houses. It touches neither the 1st house nor the 8th.

Now watch the three methods take different roads out of that. Pindayu would read the exact degree of every planet, so its largest single question here would be how much a Jupiter combust at a tenth of a degree loses to the reduction for combustion, and Jupiter in this chart is the 8th lord. Amsayu would not ask that question at all. It would ask which navamsha division each planet stands in, where Jupiter at 28.74 degrees of Gemini sits in the ninth and last division of its sign. A birth time twenty minutes out cannot move that, because Jupiter was covering about a fifth of a degree a day at the time, but a birth date a week out would: it stood one and a quarter degrees short of leaving Gemini altogether. Nisargayu would ignore both questions, give Jupiter its fixed allotment, and produce the same contribution it would produce in any chart anywhere.

Three methods, one chart, three different questions asked of the same Jupiter. That is why no number appears here. The disagreement sits upstream of the arithmetic, so agreeing on the arithmetic would not settle it.

What the engine will say about this chart is dated and checkable. Vimshottari, which is the 120-year cycle of planetary periods Indian astrology runs on, puts a twenty-year Venus period from 17 March 2004 to 17 March 2024, a six-year Sun period from 17 March 2024 to 18 March 2030 which is the one running today, and a ten-year Moon period from 2030 to 2040. The free tool that scores past periods for difficulty returns two rows for this chart as of 26 August 2026: 11 May 2025 to 5 April 2026, eleven months, and 16 January 2023 to 17 March 2024, fourteen months, both banded as uneven rather than hard, with the claim that good periods and flat ones sat close together. For this chart the tool did not find a severe period anywhere in the checkable past, and it reports the two mixed ones it did find rather than reaching for something worse. Both are claims the person whose chart it is can mark right or wrong from memory, which is what a bracket covering thirty years cannot be.

If an astrologer has already given you a number

This is the situation most people arrive in, and it deserves a direct answer.

Ask which of the three methods was used. If the answer is not Pindayu, Amsayu or Nisargayu by name, the calculation was not one of the three. Ask why that method rather than the other two, because the choice is a step inside the method and it has a stated basis. Ask what birth time was used and where that time came from, then set it against the table above: at thirty minutes of uncertainty, the rising sign the whole reading stands on is right about half the time.

Then look at what you are being asked to do with the answer. A bracket spanning thirty years cannot tell you whether to take the job, move countries, have the child, or start the treatment. Those are the decisions people actually make under this fear, and none of them is improved by a category that wide. If a reading has already changed a real decision in your life, the thing to check is whether that decision would still make sense if the bracket were the one next door, because there is a meaningful chance that it is.

And if you were given a year, treat that as the strongest available signal about the source. The classical method does not produce a year. It produces a bracket, under a chosen method, with stated reductions, and the texts themselves list conditions that alter what the bracket describes. A single year is an invention laid on top of a calculation that does not support one.

What your own chart can tell you today

The parts of the chart an ayurdaya calculation reads are worth reading. They are worth reading for questions that can be answered.

The free hard-years tool takes your birth date and names the most demanding periods of your life so far, with dates, from your planetary periods alone. Nothing about your life is looked up, and the dates are specific enough to be wrong, which is the point of putting them in front of you first.

The free kundli gives you your rising sign, your 8th house, its lord and where that lord sits, so you can check your own chart against the placements described here. The [free dasha calculator](/free- tools/dasha) gives you the period sequence every timing claim is built from.

If you want to talk it through, the chart chat reads your own chart and will not put a clock on your life. Ask it about the 8th house, about Saturn, about a period you are in the middle of, and it answers from your placements. Ask it when you will die and it declines, on purpose.

Related reading

• D8 Ashtamsa chart is the definitional page for the division most often named in longevity work. This page covers the same ground with the limits stated.
• Divisional charts explained covers which vargas belong to the classical sixteen, which sit outside them, and which six AstroMedha computes.
• Sarala Yoga is the classical reading of a strong 8th lord placed in the 8th house, and it is read as favourable.
• Free hard-years tool for the dated periods your own chart has already run through.
• Free kundli for your rising sign, your 8th house and its lord.
• Free dasha calculator for your period sequence.
• All Vedic insights and all free tools.