What is Synastry?

Synastry is relationship astrology. It compares two natal charts to reveal how two people affect each other emotionally, mentally, romantically, and practically. Instead of asking “Are our Sun signs compatible?”, synastry asks:

How does your Venus connect to their Mars?
Do your Moons support each other?
Are there Saturn ties that build commitment (or create pressure)?
Where do their planets land in your houses (your life areas)?

Synastry is not about “good” or “bad.” Every relationship has gifts and challenges. The value is clarity: once you see the pattern, you can work with it consciously.

How Synastry Works (in practice)

1) Planet-to-planet aspects

These aspects describe how your inner parts interact.

Venus–Mars: chemistry, desire, attraction style
Moon–Moon: emotional comfort and day-to-day vibe
Sun–Moon: core compatibility and life-direction resonance
Mercury–Mercury: communication style
Saturn contacts: responsibility, commitment, tests, longevity

Harmonious aspects (trines/sextiles) often feel easy. Challenging aspects (squares/oppositions) create tension — but also growth and passion if handled well.

2) House overlays

House overlays answer: “Where do they ‘land’ in my life?”

Examples:

Their planets in your 1st house: identity impact, strong presence
Their planets in your 5th house: romance, fun, creativity
Their planets in your 7th house: partnership focus
Their planets in your 8th house: intensity, deep bonding, transformation
Their planets in your 10th house: public image, career influence

House overlays are why birth time can matter: house boundaries depend on time.

Key Synastry Signatures You’ll See

Venus–Mars (chemistry)

Conjunction: strong mutual attraction
Trine/sextile: natural romantic harmony
Square/opposition: high tension (often passionate) — requires emotional maturity

Moon contacts (emotional safety)

Trines: easy empathy
Squares: different emotional rhythms
Oppositions: complementary but polar — can be magnetic

Saturn contacts (long-term)

Saturn connections can feel “serious.” They can stabilize a relationship or create a sense of pressure. Healthy Saturn means commitment and reliability. Unhealthy Saturn can feel like judgment or fear.

Common Misconceptions

“Challenging aspects mean we’re doomed.” Not true. Some friction is necessary for growth.
“Good synastry means no work.” Also false. Even easy charts need communication.
“Synastry replaces real compatibility.” It highlights patterns — your values and actions still matter.

Practical Tips for Using Synastry

Use synastry to improve communication (Mercury contacts).
Use it to understand conflict triggers (Mars and Saturn contacts).
Use it to strengthen intimacy (8th house overlays, Moon aspects).
Use it to choose timing for important talks (with transits).

Next Steps

After synastry, many couples explore:

A natal chart deep-dive for each person
Daily horoscopes personalized to each chart
Transit tracking to understand phases of the relationship

Free Synastry Chart Calculator - Relationship Compatibility