Relationships

Synastry: How to Check Compatibility Using Natal Charts

February 10, 2026
blog.updated August 12
20 min read
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Synastry: How to Check Compatibility Using Natal Charts

Why do we understand one person perfectly, while with another it's as if we're speaking different languages? The answers are provided by Synastry — the technique of overlaying two natal charts.

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Levels of Compatibility

1. Psychological Comfort (Moon + Moon, Moon + Sun)

The most important for marriage. Harmonious Moons means you feel comfortable together. Sun-Moon conjunction is a classic marriage aspect.

2. Mutual Understanding (Mercury + Mercury)

Do you have things to talk about? Conflicting Mercuries lead to heated arguments. Harmony means best friends.

3. Attraction (Venus + Mars)

His Mars to her Venus — a spark, flirtation, passion.

Conflicting Aspects

  1. Mars — Mars: Constant quarrels, competition.
  2. Mars — Saturn: One acts, the other forbids. Coldness.
  3. Mars — Pluto: Aspect of violence. Strong tension.

3 or more conflicting aspects — the union will be very difficult.

Seal of Fortune and Misfortune

Seal of Fortune 🍀 — a harmonious aspect of Jupiter to the partner's Sun/Moon. Things "go well" for you when you're with them.

Seal of Misfortune ⚡ — a tense aspect of Saturn to the Sun/Moon. The partner feels suppressed.

Sexual Compatibility

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  1. Venus (F) — Mars (M): Classic. Even a square gives "African passions."
  2. Moon — Mars: Aspect of intimacy.
  3. Pluto to Venus/Mars: Fateful, obsessive passion.

Karmic Connections

Lunar Nodes: Partner's planets on your Nodes — a karmic meeting.

Lilith: An aspect to a partner's planets creates obsession and dependent relationships.

Analysis Algorithm

  1. Look at expectations (each person's Venus).
  2. Overlay charts — do planets fall into the 7th house?
  3. Look for conflicts (Mars, Saturn, Pluto).
  4. Look for happiness (Jupiter, harmonious Moons).
  5. Look at sex (Venus and Mars).

FAQ

Is 100% compatibility possible?

No. Perfect harmony often leads to boredom. Squares are needed for growth.

What to do with poor compatibility?

"Bad" synastry requires work, but often provides the most powerful personal growth.

👉 Calculate compatibility now

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