D7 Chart Calculator (Saptamsa)

A sign in sevenths

Each saptamsa is 30° divided by 7, and the boundaries inside any sign fall, to the nearest second, at 4°17′09″, 8°34′17″, 12°51′26″, 17°08′34″, 21°25′43″ and 25°42′51″. A longitude already rounded to the minute, as most printed tables are, can sit on the wrong side of one of these lines, so the placement has to be computed from the full-precision position rather than from the figure on display.

The rule for assigning signs is brief. In an odd sign the seven parts are counted from the sign itself. In an even sign they are counted from the seventh sign from it, its opposite. So the first saptamsa of Aries is Aries, while the first of Taurus is Scorpio — and because seven steps from the opposite sign lead back home, the last saptamsa of every even sign is that sign once more, just as the first saptamsa of every odd sign is.

Applied to the example, the Rasi lagna at Scorpio 11°23′ lies in the third part, between 8°34′ and 12°51′. Scorpio is even, so the count opens at Taurus and runs Taurus, Gemini, Cancer: a Cancer D7 lagna. Its degree, 19°44′, is the distance covered inside that third part multiplied by seven.

Kshara to Shuddha jala: the seven named parts

Brihat Parasara Hora Sastra names the seven saptamsas after seven liquids: Kshara (salt water), Kshira (milk), Dadhi (curd), Ghrita (clarified butter), Ikshu rasa (sugar-cane juice), Madya (wine) and Shuddha jala (pure water). In an odd sign they run in that order; in an even sign, in reverse, so an even sign opens with Shuddha jala and closes with Kshara.

The example's lagna sits in the third part of an even sign, and three steps along the reversed list — Shuddha jala, Madya, Ikshu rasa — place it in Ikshu rasa. The Moon at Aquarius 3°18′ is in the first part of an odd sign, which is Kshara. The names echo the seven oceans of Puranic cosmology. The calculator does not print them, and how much a reader makes of them depends on the school.

Why the D7 is read for progeny

Chapter 7 of the same text, which allots each division its subject, gives the saptamsa to sons and grandsons. Modern practice takes that as progeny in general — children of any gender and the family line that continues through them. It is the classical basis for using the D7 for children, and it is a narrower brief than the navamsa's.

The usual order of attention runs: the D7 lagna and its lord; the fifth house of the D7 with its occupants and lord; the position in the D7 of the Rasi chart's own fifth lord; and Jupiter, the natural significator of children. Those are the factors a reading collects. Questions of conception, pregnancy or fertility are medical, and no divisional chart answers them.

What the fifth-house callout gives you

The result singles out the fifth house of the saptamsa because the fifth is the house of children in any chart, and here it is the fifth of a chart that is itself devoted to children. The callout gives the sign on that house, lists whatever stands in it, and says which sign and which house of the D7 its lord occupies.

An unoccupied fifth is no cause for alarm; most houses in most charts are empty. In that case the lord carries the house, and a reader looks at the lord's sign, its distance from the D7 lagna and the company it keeps. When the fifth does hold planets, they are read alongside the lord, not instead of it.

The 1961 saptamsa, placement by placement

The worked example's D7 lagna is Cancer, with Rahu in it at 13°52′ and Ketu opposite in Capricorn, the seventh house. Counting from Cancer, the fifth house is Scorpio, and it is occupied: the Sun at 11°58′ and Mars at 15°24′. Mars is Scorpio's lord, so the fifth lord of this D7 sits in its own sign, inside the fifth house it rules.

Elsewhere, Venus at 25°53′ and Saturn at 0°00′ share Leo, the second house; Jupiter at 1°51′ and Mercury at 29°02′ share Libra, the fourth; and the Moon is in Aquarius, the eighth, at 23°09′ — so the lord of the Cancer lagna sits eighth from it. The Rasi chart's fifth lord is Jupiter, since the D1 lagna is Scorpio and its fifth sign is Pisces, and in the saptamsa Jupiter lands in the fourth house.

Five bodies keep their Rasi signs. The Sun and Mars, late in Scorpio, fall in the last part of an even sign and come back to Scorpio; Rahu, late in Cancer, and Ketu, late in Capricorn, do the same; the Moon, early in Aquarius, is in the first part of an odd sign and stays put. That follows from where the degrees happen to fall, and the table records it without comment.

Fine margins, and what the D7 cannot do

Saturn's row is the clearest caution on the page. It is printed at Capricorn 4°17′ in the Rasi and at Leo 0°00′ in the D7: its true longitude lies at most a few seconds of arc beyond the first boundary, 4°17′08.57″, so it has only just left the first part of Capricorn, which maps to Cancer, for the second, which maps to Leo. An ayanamsa just nine seconds of arc larger than the Lahiri value used here would return Saturn to Cancer, the sign of the D7 lagna. Mercury, at 29°02′ Libra, is likewise under ten minutes of arc from crossing into Scorpio and the fifth house.

The D7 lagna moves on roughly every seventeen minutes on average, and the example's rising degree sits about one and a half degrees short of the next boundary — a handful of minutes of clock time. A birth time rounded to the nearest quarter hour is not enough to fix the D7 houses with confidence.

Finally, the D7 refines the Rasi chart and is read together with the D1's fifth house and its lord, never as a free-standing verdict on whether, when or how many. Uranus, Neptune and Pluto are not part of the classical scheme and do not appear. Timing, as with every division, belongs to the dashas.

Which house in the D7 chart is for children?

The fifth, counted from the D7's own lagna. Readers note the sign there, any planets in it and the placement of its lord, then add the D7 lagna, Jupiter and the Rasi chart's fifth lord. Together these are descriptive factors read with the birth chart, not a count of children or a forecast of any kind.

How is the saptamsa chart calculated?

Divide a body's degree within its sign by 30/7, about 4.2857, to see which of the seven parts it occupies. In an odd sign the first part belongs to that sign and each later part to the next sign in order; in an even sign the sequence starts from the opposite sign. The leftover distance into the part, times seven, gives the D7 degree.

Is saptamsha the same as the D7 or saptamsa chart?

Yes. Saptamsa and saptamsha are two spellings of the Sanskrit for a seventh part, and D7 is the numbered shorthand used in software and textbooks. All three name the chart made by cutting each sign into seven equal portions and assigning them signs under the odd-and-even rule.

Can the D7 chart predict whether I will have children?

No chart can responsibly answer that, and this page does not try. The saptamsa sets out the classical factors for progeny — the fifth house, its lord, Jupiter — as one part of a whole-chart reading. Questions about fertility or conception belong with a doctor; astrology is not a medical assessment of any kind.

Why did my D7 chart change when I adjusted the birth time?

Its lagna enters a new saptamsa each time the rising degree crosses another 4°17′, which takes a little over a quarter of an hour on average. Every house, the fifth included, is counted from that lagna, so a small change of time can move them all at once. The planets' D7 signs change far less often, the Moon apart.

How is the D7 different from the fifth house of the birth chart?

The Rasi chart's fifth house is the broad statement about children, intelligence and past merit; the D7 is a finer division devoted to progeny alone. Readers start with the D1 fifth house and its lord, then turn to the saptamsa to see how those indications are qualified. Where the two agree, a reading rests on firmer ground.