How to determine the strongest planet(s) in a chart

In order to interpret charts, it is very important to determine the strongest influences within the chart. Among the factors that will have the most influence on a person are:

A. The strongest aspects in the chart, especially the strongest energetic aspects (conjunction, square, opposition, and to a lesser degree semisquare and sesquare).

B. Clusters of planets in one place (called stellia), i.e. in one sign or all conjunct within orb.

C. Overall chart patterns like T-squares in Western astrology and Yogas in Vedic astrology.

D. The weakest planets in the chart (e.g. combust, weak by sign, etc.) have significant disruptive effects on life themes.

However, the strongest planets in a person's chart often represent pre-eminent influences, and therefore it becomes vital to be able to ascertain what planets are strongest.

Principles of Planetary Strength

1. Planets that are conjunct or square the Ascendant within 5 degrees (and preferably less) are among the strongest planets in the chart. Planets tightly opposed the Ascendant may have strength too, but usually to a lesser extent.

2. Planets that have no planets on either side of them for at least 60 degrees (two signs) become "bucket handles" and have great impact.

3. Planets that are retrograde are very strong and "Full", i.e. closest to the Earth and visibly largest, and have a major impact (with the exception of the "invisible" planets Uranus, Neptune, and Pluto which are retrograde quite often).

4. The Moon when it is within one sign of Full is very strong.

5. Planets with essential dignity, i.e. in their own sign (rulership) or exaltation, are very strong.

Important note: I have been practicing Western astrology for 35 years and Vedic astrology the past 13 years and have come to realize that planetary strength should be ascertained using the Sidereal Zodiac (with the Lahiri ayanamsha) and not the Tropical Zodiac. For years, as a Western astrologer, I tried to use strength-via-sign-placement in the Tropical Zodiac and never got effective results. As soon as I started using the Sidereal Zodiac, it became immediately apparent that this approach worked.

6. Planets with directional strength are very strong. Mercury and Jupiter are strongest when in the First House, Venus and Moon when in the Fourth house, Mars and the Sun (and the South Node) when in the Tenth House, and Saturn (and the North Node) when in the Seventh House.

7. Because every chart is unique, there will arise other considerations that will make a particular planet strong in a specific chart beyond the above-listed factors.

Application of Planetary Strength

I. Strong planets influence all planets that they aspect, and all houses that they aspect. (Note: in both Vedic and Hellenistic astrology, planets aspect empty houses, not just planets.)

II. Strong planets will magnify the potency of planetary patterns (as introduced in point C above).

III. Strong planets in the birth chart will also be more influential as transiting planets. (The principle being that transiting planets affect different charts differently, partially due to each planet's strength in the birth chart.)

IV. In comparing the effects and influence of two or more planets in conjunction, the strongest planet wins.

V. The strongest of: the house occupants, planets that aspect a house, and the house ruler will have the most influence on the themes of that house.

VI. The strongest planet to influence the First House often has the greatest effect on a person's life. This includes the aforementioned First House occupants, planets that aspect the First House, the First House ruler, and the planets that aspect the First House ruler.

The above principles just touch on a few of the many effects of strong planets upon a chart.



Meryl Streep's chart illustrates many of the principles of this article. Her Jupiter is strong because it is retrograde, close to the Descendant, and alone in half the sky (a bucket handle). Yes, it is at the descendant, which I said gives it less strength, and yes, it is in its weakest sign in the Vedic chart.

But in a way, this is fortunate for us, because it invites me to share a principle that I have learned from my Vedic guru Hart de Fouw: a planet's weakness does not affect its strength. A planet that is strong and weak will manifest both strength and weakness. You don't "mush" the two together and call it mediocre. [Which is why all formulaeic methods of determining planetary strength, like Astrodynes, fail miserably. They ignore this principle.}]

Even if you did "mush" the strength and weakness together, you would be adding two-and-a-half strengths (bucket handle, retrograde, and 1/2 at the Descendant) to only one weakness, and still end up with Jupiter being the strongest planet in the chart.

I think the following quote attributed to Ms. Streep sums up her Jupiterian wisdom, openness, etc.:

"Listening is everything. Listening is the whole deal. That's what I think. And I mean that in terms of before you work, after you work, in between work, with your children, with your husband, with your friends, with your mother, with your father. It's everything. And it's where you learn everything." [From the IMDB.COM bio]


Tom Hanks provides us with additional practice. It is apparent, even from the Western chart, that Tom's Venus is pre-eminent, because it is at the top of the chart and retrograde, closest to the Ascendant's degree. We may also include retrograde Saturn among the strong planets, and even Mars, although it is farther from an angle, and the angle is the Decendant, to boot.

In the Vedic chart, Venus is additionally in its own sign, confirming even more strongly its pre-eminence. Note too, however, that the Moon is in its own sign of Cancer, and is therefore quite strong in a way that is not apparent in the Western chart.

It is clear that Tom Hanks embodies many of the qualities of Venus: he's a "soft" man, keeps a lot inside (according to his wife in the IMDB quote: "My wife keeps on telling me my worst fault is that I keep things to myself and appear relaxed", is charming and likeable, is creative (has written scripts and even music), and is, to quote an interview with Lynn Barber in the at "Nice nice nice nice nice" [Nice is a Venus word] and was "charming and courteous and friendly and helpful" during the interview even though he had a nasty cold at the time and she deliberately tried to needle him.

The assessment of the strongest planet(s) is an important part of interpreting any chart. Just remember my other "points of emphasis" at the top of this article, such as planets receiving the strongest aspects. Astrology is a wonderful enterprise, and the journey gets richer and more magical the more you understand.

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