Synthesis Astrology

Synthesis Astrology calculates your sign composition. Instead of reducing you to one sun sign, it shows how the placements in your birth chart spread across the zodiac when three systems are read together.

Give it your birth date, birth time and birthplace. It looks up your birthplace in an offline place database and asks you to confirm the right match, then calculates your planets and angles in three zodiacs: Tropical, True Sidereal (13 signs, including Ophiuchus) and Draconic. It weights those placements into one set of sign percentages and shows your dominant signs, the placements behind each sign, and a few questions to reflect on. You can also ask how the method works, how the percentages are weighted, or why the zodiacs give you different signs.

It is for anyone curious about astrology, including people comparing tropical and sidereal astrology, who want to see their chart as a mix rather than a single label.

Limitations: the composition is an interpretive model, not a scientific measurement, and it does not predict events. If you don't know your birth time, it calculates from local noon and leaves out the Ascendant and houses. Your birth details are used only to calculate the result and are not stored.