How to use
- 1
Enter birth date, time and city for person A (you) and person B.
- 2
Look at the bi-wheel: A is inside with A’s houses, B’s planets are in the outer ring.
- 3
Read the A × B aspect grid and list, sorted from the tightest aspect.
- 4
Check the house overlays and the element balance of both charts.
How synastry works
Synastry lays one chart over another. The main tools are inter-aspects, the angles between A’s planets and B’s planets, and house overlays, which houses of one chart the other person’s planets fall into. In astrological tradition, contacts between the Sun, Moon, Venus and Mars are read for attraction and ease, and contacts with Saturn for commitment and friction.
Why there is no compatibility score
A single percentage hides more than it shows: it depends entirely on which aspects someone chose to count and how. This tool lists the actual contacts with their orbs so you can see what a score would be built from. Tight aspects (small orb) are traditionally given more weight than wide ones.
Frequently asked questions
Do both people need a birth time?
Aspects between planets work without times, although Moon aspects can be a few degrees off. House overlays need the birth time of the person whose houses are used.
What is the difference between synastry and a composite chart?
Synastry compares the two charts directly. A composite chart builds one new chart from the midpoints of both, which this tool does not do.
Is person B’s data saved?
No. Only your own data (person A) is remembered on this device; person B is cleared when you leave the page.