Relationship astrologyScientific method

Synastry – real
relationship compatibility

Not 'Aries suits Leo.' Synastry compares two natal charts planet-by-planet – hundreds of factors instead of one zodiac sign.

How synastry works

The mechanics behind chart comparison

Synastry overlays two natal charts and calculates the angular distance between every planet in one chart and every planet in the other. These angles are called aspects – and each one describes a specific type of interaction.

Conjunction (0°)

Merging of energies. The most powerful aspect – two planets operate as one. Can be both harmonious and overwhelming.

Trine (120°)

Natural harmony. Energies flow easily between partners. Feels effortless – but can lead to passivity if there are no challenging aspects.

Square (90°)

Tension and friction. Creates conflict – but also passion and growth. Many long-term couples have strong squares in synastry.

Opposition (180°)

Polarity and magnetism. Opposite qualities attract – but require conscious balance. Often felt as strong attraction mixed with frustration.

A full synastry analysis examines all 10 planets + Ascendant + Lunar Nodesof both people. That's over 100 potential aspects – each telling a part of the story.

Key planets in synastry

What each planet reveals about your relationship

Sun

Aspects between Suns show how well your life goals and sense of identity align. Sun conjunction – a powerful sense of being 'the same breed.' Square – ego clash, a struggle for dominance in the relationship.

Moon

The Moon governs emotional compatibility. Moon-Moon aspects determine whether you feel 'at home' with your partner. Moon trine – intuitive understanding without words. Square – different emotional needs.

Venus

Venus is the planet of love and values. Venus aspects to the other person's planets show what attracts you to each other. Venus-Mars – sexual chemistry. Venus-Jupiter – mutual enrichment and generosity.

Mars

Mars is the energy of action and passion. Mars aspects reveal conflict dynamics and sexual attraction. Mars-Mars conjunction – explosive energy. In square – frequent arguments, but intense passion.

Jupiter

Jupiter is the planet of growth and expansion. Jupiter aspects to personal planets bring a sense of luck and ease in the relationship. Jupiter-Venus – one of the best marriage aspects: joy, support, abundance.

Saturn

Saturn is the planet of responsibility and time. Saturn aspects to personal planets add seriousness and longevity. Trine – a stable foundation. Square – a feeling of restriction, control, 'I can't be myself.'

Neptune

Neptune is the planet of illusions and idealization. Neptune aspects to personal planets create a sense of 'magical' connection. Trine – spiritual closeness. Square or opposition – rose-colored glasses, deception, disillusionment upon 'awakening.'

Synastry vs sign compatibility

By zodiac sign
  • 1 factor – Sun sign only
  • 12 possible 'types'
  • All Leos are identical
  • Ignores Moon, Venus, Mars
  • No aspects calculated
  • Entertainment, not analysis
Synastry
  • 100+ aspects between charts
  • 10 planets + nodes + angles
  • Unique for every couple
  • Venus, Mars, Moon – key factors
  • Precise degree calculations
  • A relationship diagnostic tool

Sign compatibility uses 1 data point. Synastry uses hundreds. The difference is like comparing a weather forecast by season vs. by satellite data.

Ready to see your real compatibility?

Enter two birth dates – get a full synastry analysis with all aspects, scores, and personal interpretation.

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