Bhrigu Bindu Calculation: Two Formulas for the Moon-Rahu Midpoint

Ask two Bhrigu Bindu calculators for the same chart and they can disagree by exactly half the zodiac. Neither has made a slip. Two formulas for the point are in use, and for roughly half of all positions of the Moon and Rahu they give opposite answers. This page sets out both, proves where they part, and works three examples through to sign, degree, nakshatra and pada.

Bhrigu Bindu Meaning (भृगु बिंदु)

Bindu means a point. The Bhrigu Bindu is the point halfway between the Moon and Rahu in the birth chart, and it belongs to modern Vedic practice: this site has not traced it to a classical text, and it attributes the technique to no particular text or author. Those who use it apply it to timing, by watching for transits over it. That use is reported here and nothing more; the page computes where the point is and gives no timing from it.

The Two Formulas in Use

Write the Moon’s sidereal longitude as M and Rahu’s as R, both from 0° to 360° counted from 0° Aries.

• Convention A, the forward arc. Measure from Rahu forward through the signs until you reach the Moon, halve that arc, and add it to Rahu: BB = R + ((M − R) mod 360) ÷ 2.
• Convention B, the plain average. Add the two longitudes and halve the sum: BB = (M + R) ÷ 2.

Convention A lands, in every case, on the stretch of zodiac running forward from Rahu to the Moon, whether that stretch is shorter or longer than half the circle. Convention B pays no attention to direction; it treats the two longitudes as ordinary numbers.

When the Two Agree, and When They Are 180° Apart

If M is at least R, the forward arc from Rahu to the Moon is simply M − R, and Rahu plus half of it is (M + R) ÷ 2: the two conventions give the same point. If M is less than R, the forward arc has to pass 0° Aries and is M − R + 360. Half of the extra 360° is 180°, so convention A lands exactly opposite convention B. No other outcome is possible.

To check the algebra, both formulas were run on every pair of whole-degree longitudes, 1,29,600 pairs in all. They agreed on 64,980 and were exactly 180° apart on 64,620, or 49.9%; no pair gave any other gap. The share falls just short of a half only because of the 360 pairs in which the Moon and Rahu hold the same degree, which agree; the remaining pairs split evenly. This is a property of the arithmetic, not of anyone’s chart.

What the 180° Gap Does to the Sign, Nakshatra and Pada

Half the zodiac is six signs, so when the conventions disagree the degree within the sign stays the same and the sign changes to the 7th from the other. It is also 54 padas, thirteen and a half nakshatras, so the nakshatra changes too, and the pada moves two places on. Every one of the 64,620 disagreeing pairs on the grid shows all three. For a search such as “bhrigu bindu in 7th house” this has a plain consequence: counting houses by whole signs from the lagna, a chart whose Bhrigu Bindu is in the 1st house by one convention has it in the 7th by the other, and the same swap holds for any pair of opposite houses. Before any reading of a house placement, it helps to know which convention produced it.

Worked Examples: Sign, Degree, Nakshatra and Pada

The longitudes below are chosen to show the arithmetic. They are examples, not anyone’s chart.

In Example 1 the Moon, at 100°20′, has a smaller longitude than Rahu at 295°40′. The forward arc from Rahu runs through Aquarius, Pisces and on to Cancer, 164°40′ in all; half of it added to Rahu gives 18°00′ Aries. The plain average is 198°00′, which is 18°00′ Libra, the opposite point. Example 2 is the same situation, with Rahu in Aquarius and the Moon in Aries. In Example 3 the Moon’s longitude is the larger, and both formulas give 10°20′ Aquarius, in Shatabhisha pada 2, whose arc is Aquarius 10°00′ – 13°20′. The nakshatra and pada columns use the same 3°20′ padas as the site’s nakshatra pages.

Where Rahu Was: The Site’s Node Table

The calculation needs Rahu’s longitude at birth. The site’s node table gives the sign Rahu occupied for any date from 2024 to 2031. It is generated from the mean node and gives days only; the true node swings either side of the mean one, so a true-node ephemeris can place a sign change some way from these dates, and a birth near the edge of a row is worth checking in one.

The first and last rows are cut off by the table’s range; the four full rows each last 566 or 567 days, which works out to about 0.053° a day of backward motion. A birth between 5 Dec 2026 and 23 Jun 2028, for instance, has Rahu in Capricorn; the transit itself is covered on the Rahu-Ketu Capricorn-Cancer page. A sign is not a degree, though. With the Moon in some other sign, letting Rahu range across all 30° of its sign moves either formula’s answer across a stretch of 15°, half a sign, so the sign alone narrows the Bhrigu Bindu without fixing it.

A Point Fixed at Birth

In a birth chart the Bhrigu Bindu does not move: it is worked out once from the two positions at the moment of birth. The same arithmetic applied to the sky on successive days gives a point that moves quickly. The Moon gains about 13.2° a day (measured over 2027 with the site’s lunar ephemeris) while Rahu slips back about 0.053°, so the midpoint advances about 6.6° a day, roughly a quarter of a degree for each hour. A birth time that is an hour out shifts the Bhrigu Bindu by that much; a wrong birth date can move it into another nakshatra.

Each formula also has a seam. Convention A jumps by 180° at the moment the Moon overtakes Rahu, because the forward arc collapses from nearly 360° to nearly nothing. Convention B jumps by 180° when the Moon (or Rahu) passes 0° Aries, and is smooth where A jumps. The seams are also where the two formulas switch between agreeing and disagreeing, so with the Moon close to Rahu or close to 0° Aries, a small error in either position decides whether two calculators match.

What This Page Does Not Do

It locates a point and stops there. It does not say what the Bhrigu Bindu in the 7th house or any other house means, what a transit over the point brings, or when anything in a life will happen; practitioners of the technique time events by it, and this page publishes no such timing. Nor does it say that one convention is right. For Rahu’s own aspects, see Rahu and Ketu drishti; the free kundli prints the Moon’s sign, its degree in that sign, and its nakshatra and pada, but not Rahu. In Hindi: भृगु बिंदु कैसे निकालें: दो सूत्र, 180° का अंतर.