Moon Phase Compatibility Calculator
Enter two birth dates. We find each person's natal moon phase and read what traditional lunar astrology says about your match.
Want a deeper read on your own phase?
Take the free moon phase personality test. 20 questions, 3 minutes, plus a written profile of your lunar archetype.
Take the Free Moon Phase TestHow the calculator works
The tool runs a standard astronomical calculation. It measures the time between your birth date and a reference new moon (January 6, 2000), divides by the average lunar cycle of 29.53 days, and finds where in the cycle your birth fell.
The result is one of eight named phases, from New Moon through Waning Crescent. Each phase carries a traditional archetypal meaning in lunar astrology: a way of starting things, an emotional rhythm, a tendency toward initiation or reflection.
Compatibility is then read by the distance between your two phases on the cycle. Adjacent phases flow into each other (Flow Match). Phases a quarter cycle apart create generative tension (Building Match). Opposite phases produce magnetic polarity (Polar Match). Same-phase pairs see each other clearly but can reinforce shared blind spots (Mirror Match).
Important caveat: moon phase astrology is a symbolic and reflective system, not an empirical science. Use the result as a conversation starter, not a verdict on whether your relationship will last. Real compatibility tracks communication, shared values, and effort, not lunar geometry.
What each phase means in relationships
starts things, sees possibility, loves fresh beginnings.
grows through connection, curious, adjusts and learns.
direct, confronts problems, makes clear choices.
nurturing, careful, gives effort and attention.
magnetic, expressive, big emotional intensity.
generous, wise, gives steady presence.
knows what they need, exits clearly, values depth.
introspective, imaginative, processes inwardly.