D7 Saptamsa Chart Calculator
A free saptamsa (D7) chart calculator — seven parts of 4 degrees 17 minutes per sign, counted from the sign itself in an odd sign and from its opposite in an even one.
The Saptamsa is the seven-fold division: each 30-degree sign is cut into seven equal parts, and a planet moves to whichever part its exact longitude falls in. One part is 30/7 degrees — 4 degrees 17 minutes and about 8.6 seconds. Thirty degrees is 108,000 arcseconds, and one through six all divide it exactly; seven does not, so none of the six boundaries inside a sign lands on a whole arcsecond.
The count turns on whether the sign is odd- or even-numbered. In an odd sign — Aries, Gemini, Leo, Libra, Sagittarius, Aquarius — the run of seven starts from that sign itself; in an even sign, from the seventh sign from it, the sign opposite. Classically, in the Parashari varga tables, this is the varga consulted for matters of children. Kundli Studio divides the computed longitude rather than reading a rounded table.
The seven saptamsas of Aquarius
Aquarius is the eleventh sign, so it is odd and its seven saptamsas begin from Aquarius itself. Every internal boundary falls on a fraction of an arcsecond. In a sample chart for 1 January 1990, 12:00 noon IST at Chennai — a fabricated datum, never a real birth — the Moon sits at 6 deg 27' Aquarius.
| Part | Arc within Aquarius | Saptamsa sign |
|---|---|---|
| 1 | 0 deg 00' 00" - 4 deg 17' 09" | Aquarius |
| 2 | 4 deg 17' 09" - 8 deg 34' 17" | Pisces |
| 3 | 8 deg 34' 17" - 12 deg 51' 26" | Aries |
| 4 | 12 deg 51' 26" - 17 deg 08' 34" | Taurus |
| 5 | 17 deg 08' 34" - 21 deg 25' 43" | Gemini |
| 6 | 21 deg 25' 43" - 25 deg 42' 51" | Cancer |
| 7 | 25 deg 42' 51" - 30 deg 00' 00" | Leo |
6 deg 27' falls inside the second part, so the Moon of that sample chart is placed in Pisces in the D7. In an even sign the same degree would count from the opposite sign, landing six signs further round in Virgo.
How to read the result
In the divisional chart screen's default grid of six charts the D7 sits fifth, under the selector name D-7_saptamsa. Find the As badge and note the sign number printed in its box, because in Narasimha Rao's method odd or even decides which way the house count runs. Following the classical use of the saptamsa for progeny, his textbook takes the 5th house of the D7 for children, counting forward from an odd D7 lagna and backward from an even one.
From there the same textbook reads the 5th lord for a first child, the 7th lord for a second and the 9th for a third, each counted in the direction the lagna sets. For the 1990 chart above, the D7 lagna is Sagittarius, sign 9, so the count runs forward: the 5th is Aries, and its lord Mars sits in Leo, the 9th house, beside Jupiter.
Two significators can also be located in this cell. BPHS reads sons from the 5th counted from Guru, the natural significator, so Jupiter's sign here is a reference point, and Narasimha Rao ties achievements and happiness related to children to the chara putrakaraka — in the sample, by the engine's eight-karaka count, the Moon, which falls in Pisces in the D7. A body in brackets was retrograde at birth.
Key terms
- Saptamsa lagna
- The As sign of the D7. Whether its number is odd or even sets the direction in which Narasimha Rao counts the houses of this chart.
- Backward count
- Counting houses against the zodiac — Cancer, Gemini, Taurus and on — which Narasimha Rao applies in the D7 when its lagna falls in an even sign.
- 5th lord
- The lord of the sign in the 5th house of the D7, which Narasimha Rao's textbook reads for a first child.
- Putrakaraka
- The chara karaka for progeny in BPHS's scheme of variable significators, assigned by order of longitude; the engine counts eight karakas, Rahu included.
- Natural significator (naisargika karaka)
- A natural significator. Classically Jupiter is the natural significator of children, and Narasimha Rao reads the 5th house counted from him.
All seven parts, to the arcsecond
A saptamsa part never resolves to a whole arcsecond, so rounded printed tables drift. The calculator divides the longitude itself and places all seven parts exactly.
The odd and even count, applied
Six signs separate the even-sign count from the odd-sign one, so a hand-drawn D7 goes wrong the moment a sign number is misread. The engine reads it from the computed rasi.
Its share of the Vimsopaka weighting
In the sixteen-fold Shodasavarga the Saptamsa carries 0.5 of 20 Vimsopaka points, one of nine charts on that half-point share.
Common questions
What is the D7 chart in astrology?
The saptamsa, or D7, is the seventh divisional chart: every sign is split into seven equal arcs of 30/7 degrees, and each body is re-seated in the sign its arc points to, the count running from the sign itself for odd signs and from the opposite sign for even ones. Classically it is read for progeny.
How is the saptamsa chart calculated?
Cut the sign into seven parts of 4 degrees 17 minutes 8.57 seconds and find which part the longitude falls in. In an odd-numbered sign count that many signs forward from the sign itself; in an even-numbered sign, from the seventh sign from it.
Is Pisces an odd or an even sign in the saptamsa?
Even. Pisces is the twelfth sign, so its seven saptamsas begin not from Pisces but from the seventh sign from it, Virgo — then Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces across the 30 degrees.
Why are the saptamsa boundaries not round numbers?
Because 30 does not divide by seven. The part is 4 degrees 17 minutes 8.571 seconds, so every boundary inside the sign sits on a recurring fraction. The Dasamsa, by contrast, cuts the same sign into ten parts of exactly 3 degrees.
Do I need my exact birth time?
For the D7, yes. A saptamsa part spans about 4 degrees 17 minutes, and the ascendant crosses that much sky in roughly seventeen minutes on average — faster or slower with latitude and rising sign. A quarter-hour error can shift the D7 ascendant a whole part.
How is the D7 read when its lagna is an even sign?
By counting backward. Narasimha Rao's textbook gives the case of a D7 lagna in Cancer: the 5th counted backward is Pisces, so Jupiter, its lord, stands for a first child and Saturn, lord of Capricorn, for a second, where a lagna in Gemini, an odd sign, would give Venus and then Jupiter.