D1 Chart Calculator - Rasi Chart
A free D1 chart calculator — the rasi chart, the birth chart itself, with every body placed in the sidereal sign it occupies.
The D1 is the rasi chart: the birth chart before any division is applied. Every sign spans thirty degrees, and each body simply stays in the sidereal sign its longitude falls in. P.V.R. Narasimha Rao's textbook describes it as the case of dividing a sign into a single part, and also calls it the kshetra chakra.
Every other divisional chart starts from these positions. The navamsa, the dasamsa and the rest cut each thirty-degree sign into smaller parts and move a body according to the part it falls in; the D1 is the reference they are all measured against. The rasi chart is listed first among the sixteen vargas in Brihat Parashara Hora Shastra, and every Vimsopaka strength scheme gives it a share of the twenty points — 6 of them in the Shadvarga.
Jagannatha Hora computes the D1 from precise astronomical positions with the Lahiri ayanamsa by default, and draws it in the North or South Indian style. The divisional charts on this site are all derived from the same D1 positions, so a change of birth time moves them together.
The D1 of a sample chart
Take a made-up birth, for illustration only: noon IST on 1 January 1990 at Chennai. Its D1 puts each body in whichever sign holds its sidereal longitude.
| # | Body | D1 sign, whole degrees |
|---|---|---|
| 1 | Lagna | Pisces, 16 deg |
| 2 | Sun | Sagittarius, 16 deg |
| 3 | Moon | Aquarius, 6 deg |
| 4 | Mars | Scorpio, 16 deg |
| 5 | Mercury | Capricorn, 2 deg |
| 6 | Jupiter | Gemini, 11 deg |
| 7 | Venus | Capricorn, 12 deg |
| 8 | Saturn | Sagittarius, 21 deg |
No division is applied: the sign shown is the sign the body occupies. The lunar nodes follow the same rule: Rahu falls in Capricorn at 24 degrees and Ketu, always six signs away, in Cancer. Every other varga on this site is computed from these same positions.
How to read the result
Find the ascendant first. It carries the As mark, and every house is counted from its sign. The North Indian drawing keeps the houses in fixed places — the 1st at top centre, the others running anticlockwise — and the number in each names its sign, from 1 (Aries) through 12 (Pisces); in the South Indian drawing the boxes are fixed signs, Pisces at top left and running clockwise. Hovering any body gives its sign and degree to the second of arc.
Then read the houses from that sign. Brihat Parashara Hora Shastra draws appearance, intellect, vigour and innate nature from the ascending sign, and its chapter on judging the bhavas gives each of the twelve houses its own list — the 4th for conveyances, mother and lands, the 10th for authority, livelihood and honour. Narasimha Rao's textbook places the D1 as a whole on the physical plane of existence.
Last come the labels laid over the D1. AL, A2 to A11 and UL are the arudha padas of its twelve houses, and HL, GL and the other special lagnas are drawn on this chart alone. BPHS asks for the chart to be judged from each special lagna as from the natal lagna, planets left in place; of those Parasara defines, Narasimha Rao reads HL as the self from the angle of money and prosperity, and GL from that of fame, power and authority.
Key terms
- Lagna (ascendant)
- The ascending sign, marked As on the chart; the D1 counts its twelve houses from it, and the textbook holds that in any chart the lagna shows self.
- Bhava
- A house: the twelve bhavas, Tanu to Vyaya, run in order from the lagna, and BPHS gives each its own list of matters to be read from it.
- North Indian chart
- A diamond layout with fixed house positions; the 1st house sits at top centre, and the number in each house is the sign it holds.
- South Indian chart
- A square layout of twelve fixed sign boxes, Pisces at top left and the zodiac running clockwise; the As mark shows which box holds the lagna.
- Special lagna
- A computed point judged like a lagna; the D1 carries nine as labels — BL, HL, GL, VL, PL, IL, SL, KL and BBL.
- Hora lagna (HL)
- A special lagna that starts from the Sun's position at sunrise and moves on by one sign every hora, an hour; the D1 marks it HL.
Weighted 6 of 20 in Shadvarga
In Brihat Parashara Hora Shastra's Vimsopaka schemes the rasi carries 6 of 20 points in the six-chart Shadvarga, 5 in Sapthavarga, 3 in Dasavarga and 3.5 in Shodasavarga.
The base for every varga
The navamsa, dasamsa, drekkana and every other division are computed from the D1 longitudes, so the rasi chart is the one every divisional reading starts from.
North or South Indian style
The same D1 can be drawn in either regional layout; the placements are identical, only the drawing differs. The site lets you switch between the two.
Common questions
What is the D1 chart?
The D1 is the rasi chart — the birth chart itself. It divides each sign into one part, so every body stays in the sidereal sign it occupies. Brihat Parashara Hora Shastra reads the physique from it.
Is the D1 chart the same as the birth chart?
Yes. These four names — D1, rasi chart, lagna chart, birth chart — refer to one chart. The other divisional charts, D2 to D60 and beyond, are derived from it.
How is the D1 calculated?
Take each body's sidereal longitude — the tropical position minus the ayanamsa — and divide by thirty degrees. Discard the fraction to get the sign, counting Aries as zero; what is left over is the degree inside that sign.
Which ayanamsa does the calculator use?
Lahiri (Chitrapaksha) by default. A different ayanamsa shifts every longitude by the same amount, which can move a body near a sign boundary into the neighbouring sign.
What does a planet in brackets mean on the D1 chart?
It marks a retrograde planet. The engine reads each planet's speed in longitude at the birth moment and brackets those moving backward, and the hover text adds "(Retrograde)". Rahu and Ketu are left out of this check, though BPHS describes their motion as retrograde.
Are the houses in the D1 chart whole signs?
On this chart they are: each house is one whole sign, counted from the ascendant's sign, so a planet's house follows from its sign alone, not from its distance to the ascendant's degree. That is why each house of the North Indian drawing carries a single sign number.