Drekkana (D3): the one-third chart for siblings and courage

Last updated 25 October 2026

Enter your birth details to place each planet in one of the three drekkanas of its sign and draw the D3 beside your birth chart. After the calculator: the Parashari rule it follows, how it differs from other drekkana schemes, and what an astrologer reads from it about siblings and initiative.

How the drekkana is worked out

Each sign is divided into three equal parts of 10°. Under the Parashari rule the first part is given the sign itself, the second the fifth sign from it and the third the ninth. Because the first, fifth and ninth signs always share an element, every planet’s drekkana is in a sign of the same element as its birth-chart sign: a planet in a fire sign stays in fire, one in an earth sign stays in earth, and so on.

You enter your date of birth, time and UTC offset, plus a city or coordinates if you want the D3 lagna. The calculator computes sidereal positions with the Lahiri ayanamsa, places each planet and the lagna in its drekkana, and draws the D3 and the birth chart together. The table in the result gives each planet’s birth-chart sign and degree, which of the three drekkanas it occupies, and its D3 sign, and points out any planet sitting in the same sign in both charts. A planet within a short distance of a 10° line is flagged.

Which drekkana scheme this calculator uses

There is more than one way to assign the three drekkanas, and the choice changes the chart. This calculator uses only the Parashari drekkana, the scheme given in Brihat Parashara Hora Shastra and the one most Indian astrologers mean when they say D3: sign, fifth, ninth.

Other schemes, such as the Somanatha and Parivritti drekkanas, order the signs differently; the Parivritti drekkana, for example, simply runs the 36 drekkanas through the twelve signs in order. None is wrong, but a reading built on one cannot be checked against a chart drawn with another. If your astrologer’s D3 differs from the one here, the scheme is the first thing to ask about.

What an astrologer reads in the D3

Parashara assigns the drekkana to the happiness that comes through co-born, meaning brothers and sisters, and that is its main use in consultations. The astrologer usually starts in the birth chart, with the third house (often linked with younger siblings), the eleventh (elder siblings), their lords, and Mars, the natural significator of siblings. The D3 is then used to confirm or qualify what the birth chart shows: whether those planets keep their strength in the drekkana, which houses they occupy from the D3 lagna, and whether benefic or malefic planets dominate the D3 third house.

The second theme is courage and initiative. The third house is the house of effort, enterprise and nerve, and many practitioners read the D3 for how readily a person acts on their own behalf: starting projects, speaking up, taking risks with their own effort. Here the D3 lagna lord and the drekkana placement of Mars carry particular weight.

Two cautions apply. A chart can describe your experience of a sibling relationship, but it cannot speak for the other person, who has a chart and a life of their own. And because the first drekkana of every sign is that sign itself, roughly a third of all placements simply repeat the birth chart; a reader who presents each of those as a fresh finding is counting the same evidence twice.

The birth time and the drekkana lagna

The rising degree takes about forty minutes on average to cross a drekkana, faster for signs that rise quickly at your latitude. That is forgiving compared with the navamsa or the D10, but a rounded birth time can still sit on the wrong side of a line. The result flags a D3 lagna change within ten minutes of the time you entered, and shows the span of clock time during which the D3 lagna stays the same. If you only know the date, tick “time not known” to see each planet’s D3 sign across the day; the D3 lagna is left out.

Questions to ask your astrologer about your drekkana chart

• Which drekkana scheme do you use, and does my D3 change if you switch to another?
• What do my third and eleventh houses show about siblings before you look at the D3?
• Is Mars stronger or weaker in my drekkana than in the birth chart?
• Is my birth time good enough for the D3 lagna, or should we rely on planet signs only?
• What does the D3 add to your view of how I take initiative at work?

Before booking a session for a family question, see what to expect in an astrology reading.