Astro Compatibility Calculator

Full synastry between two complete birth charts is a separate product; this engine does not blend the two methods.
Optional. Ecliptic longitude of the first person's planet or angle, for the composite midpoint.
Optional. Ecliptic longitude of the second person's planet or angle, for the composite midpoint.
Classical aspect
Semi-sextile
Zodiac Sign Compatibility Calculator
Canonical pair key
aries|taurus
Separation between the signs
30 degrees
Ptolemaic relationship
Disjunct - no Ptolemaic configuration
Element relationship
Fire and Earth are of opposite polarity
Modality relationship
Cardinal and Fixed - different modes of action
Shared polarity
Positive (diurnal) with Negative (nocturnal)
Signs apart
1
Method used
zodiac_sign_pair (sun-sign geometry only)
Compatibility narrative status
EDITORIAL_RUBRIC_REQUIRED
Interpretation status
EDITORIAL_RUBRIC_REQUIRED
Context
general
Worked out from Claudius Ptolemy, Tetrabiblos, Book I (translated F. E. Robbins, Loeb Classical Library 435) and 1 other source.
No compatibility percentage is produced. A percentage would imply a measured success rate, and none exists.
Sun-sign geometry ignores birth time and place. Full synastry between two complete charts is a different calculation.
Sign compatibility is an entertainment convention with no demonstrated predictive validity. Nothing here should be used to make a decision about a relationship.

How this is worked out

4 steps
  1. Canonical pair key: Aries and Taurus sorted by zodiac order give "aries|taurus".
  2. Aries is sign 0 and Taurus is sign 1, so they are 1 sign apart = 30 degrees.
  3. 30 degrees is the Semi-sextile: Disjunct - no Ptolemaic configuration.
  4. Fire and Earth are of opposite polarity; modality Cardinal vs Fixed.

Results are general information, not financial, tax, legal, medical or engineering advice.