Synastry Preview
Chart comparison · Free & unlimited
Synastry is the comparison of two birth charts, aspect by aspect. Enter both sets of birth details for every contact between your personal planets, with exact orbs and a transparent preview score — free, unlimited, no signup.
How to Compare Two Birth Charts
Run a free synastry comparison between two birth charts.
- 1. Enter the first person's birth date, time, and place
- 2. Enter the second person's birth details
- 3. See every personal-planet aspect between the charts, ranked by how exact it is
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FAQ
What is synastry?
Synastry is the technique of comparing two birth charts by measuring the angles between one person's planets and the other's. Those angles — conjunctions, sextiles, squares, trines and oppositions — describe how the two charts interact.
How is the preview score calculated?
It counts the aspects between your personal planets, weights each one by how exact it is, and weights flowing aspects slightly above friction aspects. It's deliberately simple and explainable rather than a black box — and it's an orientation, not a verdict.
Is a high score a good relationship?
Not on its own. Charts with lots of easy aspects can feel comfortable and go nowhere; charts with friction aspects often produce the most durable relationships because both people keep having to show up. The aspect list matters more than the number.
Why do I need both birth times?
For the planet aspects shown here, birth times mainly improve precision on the Moon. For house overlays — which of your houses their planets land in, one of the most useful parts of synastry — exact times from both people are essential, which is why the full report asks for them.