Partner Compatibility by Birth Date or Zodiac Sign
Enter two birth dates and we will find both Sun signs, or choose the signs yourself. Open a focused reading about attraction, communication, shared strengths and likely friction — free, private and without registration.
Check your compatibility
A date-only result is a Sun-sign reading, not full relationship synastry. A complete natal comparison also needs each person’s exact birth time and place.
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What this compatibility reading actually compares
In birth-date mode, the calculator uses each date’s day and month to identify the Western tropical zodiac Sun sign. It then opens the same detailed pair reading you would get by choosing two signs directly. The result compares elements — Fire, Earth, Air and Water — and modalities — cardinal, fixed and mutable — to describe where a pair may flow naturally and where their styles may differ.
The percentage is a friendly summary of those astrological patterns, not a scientific measurement or a verdict on a relationship. Use the prompts to start a conversation about needs, affection and conflict; do not use them to decide whether a relationship can or cannot work.
Why this is not full synastry
Two people with the same Sun signs can still have very different natal charts. Full synastry compares the Moon, rising sign, planets, houses and aspects, which requires an exact birth time and birthplace for each person. If a birthday falls near a sign change, those details can also be needed to confirm the Sun sign.