Two charts
Relationship chart tools
Compare contacts between two birth charts or calculate their planetary midpoints. Each method answers a different chart question.
Synastry
See how two charts connect
Compare one person's planets and angles with the other person's. Unknown birth times keep their uncertainty visible in the contact ranges.
Compare two chartsComposite
Calculate planetary midpoints
Create a separate set of positions from each pair of natal planets. Ambiguous midpoints and unsupported houses remain unavailable.
Calculate a compositeHuman Design
Connect two bodygraphs
See which channels you complete together, which you share and where one of you leads. Both charts need an exact birth time.
Compare bodygraphsTwo ways to read the same relationship
Synastry keeps each planet attached to its person. A composite calculates a new position for each matching pair of planets.
Synastry example
One person's Sun, the other's Moon
A's Sun at 10° Aries and B's Moon at 12° Cancer are 92° apart. That is a square with a 2° orb.
The interpretation compares A's self-expression with B's emotional needs. In this example, an urge to act meets a need for familiarity.
Read both perspectivesComposite example
Two Suns, one midpoint
A's Sun at 10° Aries and B's Sun at 10° Gemini are 60° apart. Their shorter-arc midpoint is 10° Taurus.
Astrologers read this composite Sun as a theme of the relationship. It does not replace either person's natal Sun.
See the midpoint methodThese are teaching examples, not the results of your charts. The calculators use the birth details you enter.
Use the comparison as a reference
These tools report geometry under a stated astrological method. A chart contact cannot establish a person's feelings or predict a relationship's outcome. Neither tool assigns a compatibility percentage.
Enter another person's birth details only with their permission. The final step saves both charts and the comparison in your private library. Private results stay outside search indexes.
Read your contacts
Start with the planets, then the angle
The planets name the topic. The aspect describes how their themes interact. Choose the pair and aspect shown in your result.
Sun and MoonPersonal direction and emotional needs.5 guides
- Conjunction between Sun and Moon in synastryA familiar response
- Sextile between Sun and Moon in synastryA point of cooperation
- Square between Sun and Moon in synastryDifferent emotional timing
- Trine between Sun and Moon in synastryAn easy fit
- Opposition between Sun and Moon in synastryContrasting priorities
Venus and MarsAffection, preferences and initiative.5 guides
- Conjunction between Venus and Mars in synastryPreference meets action
- Sextile between Venus and Mars in synastryAn invitation to cooperate
- Square between Venus and Mars in synastryDifferent pace or priorities
- Trine between Venus and Mars in synastryAn easy response
- Opposition between Venus and Mars in synastryTwo approaches to a shared desire
Moon and MarsEmotional responses and initiative.5 guides
- Conjunction between Moon and Mars in synastryAn immediate response
- Sextile between Moon and Mars in synastryAn offer of support
- Square between Moon and Mars in synastryDifferent emotional timing
- Trine between Moon and Mars in synastryFamiliar practical support
- Opposition between Moon and Mars in synastryDifferent priorities in a shared situation
Moon and SaturnEmotional needs and responsibility.5 guides
- Conjunction between Moon and Saturn in synastryCare becomes a responsibility
- Sextile between Moon and Saturn in synastrySupport through an agreed plan
- Square between Moon and Saturn in synastryA response can feel like a rule
- Trine between Moon and Saturn in synastryReliable care becomes familiar
- Opposition between Moon and Saturn in synastryCloseness and obligation
Venus and SaturnAffection, commitment and personal boundaries.5 guides
- Conjunction between Venus and Saturn in synastryAffection becomes part of an agreement
- Sextile between Venus and Saturn in synastryMake room for a shared pleasure
- Square between Venus and Saturn in synastryA limit can be mistaken for a judgment
- Trine between Venus and Saturn in synastryFamiliar routines can carry affection
- Opposition between Venus and Saturn in synastryCare and obligation can need different things
Mercury and SaturnCommunication, feedback and practical limits.5 guides
- Conjunction between Mercury and Saturn in synastryAn idea meets a standard
- Sextile between Mercury and Saturn in synastryA question can make a plan workable
- Square between Mercury and Saturn in synastryCorrection can interrupt understanding
- Trine between Mercury and Saturn in synastryShared standards can make discussion easier
- Opposition between Mercury and Saturn in synastryPossibilities and limits need the same conversation
Each guide keeps Person A and Person B separate, with a worked example for the contact. The angle measures geometry; it does not give a compatibility score.
Compare two signs
Choose two signs for their comparison, or read one sign's relationship theme below. For a personal comparison, use both birth charts.