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 above zero no saptamsa boundary 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. Jagannatha Hora 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.
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
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 above zero 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.