Venus and Mars in synastry: what the aspects mean, checked on famous couples

In synastry (the comparison of two birth charts), attraction is read first from one person's Venus against the other person's Mars, and then the other way round. What counts is the angle between them, called an aspect when it matches one of the set angles astrologers use. Five are major: the conjunction, sextile, square, trine and opposition. Each has an orb (the tolerance around the exact angle): in our calculator 8° for the conjunction and opposition, 6.5° for the square and trine, 4.5° for the sextile. Tradition reads the conjunction as desire meeting its answer, the sextile and trine as ease, and the square and opposition as a strong pull with friction. These aspects are common: in 200,000 random pairs of birth dates, 48.9% had at least one. A birth date is enough to find them, because Venus and Mars move less than 1.3° a day. Below, all five are checked on famous couples, along with one fifty-year marriage that has none.

The five points compared between two charts

The comparison uses five points: Venus, Mars, the Moon, the Sun and the Ascendant (the degree of the zodiac rising on the eastern horizon at the moment of birth). Venus describes what draws a person in and how they like to be wanted. Mars describes how they go after what they want, and how fast. Each of the two people has both, so the pair is read twice: your Venus against your partner's Mars, and your Mars against their Venus. The two angles are independent of each other, and many couples have an aspect in one direction and nothing in the other.

The Moon is compared with the Moon and describes what each person needs in order to feel safe with the other. It matters more the longer two people stay together, and it has its own article on comparing two Moons. The Sun and the Ascendant add general temperament and first impressions.

The five Venus–Mars aspects and how often each occurs

These percentages come from 200,000 random pairs of birth dates between 1950 and 2025, with Venus and Mars calculated at noon by Swiss Ephemeris (an astronomical calculation library). The square and trine turn up most often for a simple geometric reason. Their orb reaches 6.5° to either side of the exact angle, a band 13° wide. The angle between two planets can only run from 0° to 180°, so the conjunction and opposition, which sit at those two ends, use one side of their 8° orb each: 0–8° and 172–180°.

Taken together, at least one of the five aspects appears in 48.9% of pairs, and an aspect in both directions at once in 8.1%. So having a Venus–Mars aspect with someone puts you in roughly half of all possible couples.

Venus and Mars in five famous couples

Dates and places of birth are taken from Wikidata. It gives no birth times, so each position was calculated across the whole local day of birth with three hours added on either side. A couple went into the table only if the aspect stays the same for any hour of birth of either partner. Degrees are shown for local noon, and the orb column gives its full range across that window.

Each row shows one direction. For Beyoncé and Jay-Z the reverse is a trine as well: her Mars at 1.7° Leo and his Venus right at the border between Scorpio and Sagittarius, which puts them among the 8.1% of pairs with an aspect both ways. For Bowie and Iman the reverse direction depends on the hour of birth, and for the other three couples it gives no major aspect.

The traditional labels describe the texture of attraction, and these biographies show how little they say about how a story ends. Burton and Taylor had the sextile that tradition calls easy, and they married and divorced twice. Bowie and Iman had the opposition, the aspect of swings, and stayed married for 24 years, until his death in 2016.

A fifty-year marriage with no Venus–Mars aspect

Paul Newman and Joanne Woodward married in January 1958 and stayed together for fifty years, until his death in 2008. His Venus stood at about 14.7° Capricorn and her Mars at 16.3° Aquarius, 31.6° apart. His Mars at 23.8° Aries and her Venus at 13.5° Pisces were 40.3° apart. Neither distance comes near a major aspect at any hour of birth. Ossie Davis and Ruby Dee, married from 1948 until his death in 2005, are in the same position, with no Venus–Mars aspect either way.

They belong to the majority: 51.1% of random pairs have no Venus–Mars aspect at all. The aspect describes the kind of spark astrologers look for, and its absence is the ordinary case.

What you can find without birth times

Between 1950 and 2025, Venus moved at most 1.26° a day and Mars at most 0.79°. Over a single day the angle between them changes by about two degrees at most, so Venus–Mars aspects can be found from birth dates alone. The hour matters only when an aspect sits right at the edge of its orb.

The Moon covers between 11.8° and 15.4° a day, more than any orb, so its aspects cannot be calculated without a birth time. The Ascendant goes round the whole zodiac in a day and needs the time to the minute. The pair calculator marks a point whose sign is unsettled without a birth time and leaves it unresolved.

Can two charts show orientation or preferences?

A chart shows neither of them. The idea that it might is old: in the second century Ptolemy, in the Tetrabiblos (book III, "Of Diseases of the Soul"), sorted inclinations into "natural" and "unnatural" by the Sun and Moon in masculine or feminine signs and by how Mars and Venus stood to them. That is how orientation entered astrology, as an illness to be detected. Controlled tests have never supported it. In 1985 Nature published Shawn Carlson's double-blind test, in which astrologers matched charts to personality profiles no better than chance. In 2003 Geoffrey Dean and Ivan Kelly pooled more than forty such matching studies, with nearly 700 astrologers in all, and found nothing to suggest that astrologers do usefully better than chance.

Forum lists of chart "markers" for particular tastes fare no better on the numbers. They lean on Pluto, which is outside the five points above. In 200,000 random pairs of birth dates, a Mars–Pluto square in at least one direction appeared in 14.6% of pairs, any tense Mars–Pluto aspect (conjunction, square or opposition) in 29.8% and any major one in 48.2%. Venus in Scorpio for at least one of the two came up in 18.2%. A sign that one couple in three carries cannot single anyone out.

Our pair form asks each person only for a date, time and place of birth. It asks nothing about gender or orientation, because the angles do not need them.

What our calculator shows

The free sexual compatibility calculator places the five points for both of you and reads four pairings by element (fire, earth, air or water, the family each sign belongs to): your Venus with your partner's Mars, your Mars with their Venus, Mars with Mars for pace, and Moon with Moon for what each of you needs once the first spark settles. It gives no percentage and does not store your partner's birth data. The exact angles with their orbs, and every other contact between the two charts, are in the full pair reading. For a single chart, the sexuality calculator reads your own Venus, Mars, Moon and Lilith, and the article on what your birth chart says about sexuality explains those points.

What Venus–Mars aspects cannot tell you

Venus–Mars aspects measure angles between planets. They name what two people meet in each other, and they are calculated in exactly the same way for a couple married fifty years and for two strangers who never meet. Whether a relationship exists, lasts or makes anyone happy is outside the calculation. Used as a vocabulary, they help put a name to something you already notice between you, which you can then check against experience.