How it works

Horoscop is for self-reflection and fun. It is not psychological, medical or financial advice.

Our philosophy: the stars set the scene, psychology explains the pattern, and how you treat each other writes the story. Everything here is a mirror for reflection, never a prophecy or a verdict.

What the evidence says

Controlled studies have found no predictive power for astrology on personality or on who marries whom (e.g. Carlson, Nature 1985; Voas's analysis of ~10 million UK marriages, 2007/2008). Numerology, tarot and similar systems have no empirical support either. We include them because they are rich, ancient languages for reflection, and we label them ✨ Traditional & symbolic.

The Big Five personality traits are well researched. In couples, each partner's own emotional steadiness, warmth and reliability predict satisfaction; matching each other matters very little (Malouff et al., 2010; Dyrenforth et al., 2010). The strongest predictors of relationship quality are how partners feel about this relationship: appreciation, commitment, trust, repair, fun (Joel et al., 2020, PNAS). That's why we built the Bond Check. These lenses carry the 🔬 badge. 🧭 Popular-psychology lenses (temperaments, four-letter style, nine motivations, care styles, Shadow & Light) offer useful language with limited evidence.

Calculations

Planets: the open-source astronomy-engine library (MIT licence), computed on your device. We test it against NASA/JPL Horizons: every planet lands within 30 arc-seconds, and full birth charts match Swiss Ephemeris reference charts to within a couple of arc-minutes. Tropical zodiac, geocentric apparent positions, mean lunar node. Ascendant and Midheaven from sidereal time and your birthplace. Whole-sign houses.
Time zones: historical offsets, war time and daylight saving from the IANA time-zone database. While a region still ran on local mean time, we use your birthplace's own longitude. If your birth time fell in a daylight-saving jump (a time that never existed, or one that happened twice), we tell you. You can override the offset.
Birthplaces: GeoNames cities with population over 15,000 (CC BY 4.0).
Unknown birth time: we use noon, drop the rising sign, and show both Moon signs if the Moon changed sign that day.
Vedic: Lahiri ayanamsa as defined by the Indian Calendar Reform Committee (the same definition Swiss Ephemeris and Jagannatha Hora use, matching them to about one arc-second), 27 nakshatras, and the traditional 36-point Guna Milan (Ashtakoota) with the full classical tables, including the 14 × 14 Yoni table and Vashya groups that split Sagittarius and Capricorn at 15°. The classical tables read one way (bride and groom), so we average both directions and the score works for any couple. Doshas are shown with traditional cancellations, never as warnings.
Chinese zodiac: the open-source lunar-javascript calendar (MIT). Your animal changes at Lunar New Year (the folk convention). We also show the Li Chun (start of spring) animal used in four-pillars astrology when it differs. Day Master and five-element balance come from the four pillars: the year and month pillars change at the exact solar-term moment (Hong Kong Observatory times), and the day and hour pillars use true solar time at your birthplace, as in classical four-pillars practice.
Numerology: Pythagorean letter values; Life Path reduces month, day and year separately and keeps master numbers 11, 22 and 33. Accents are removed (ł→l, ö→o).
Tarot birth cards: month + day + year, reduced to 22 or below (a method popularised by Mary K. Greer).
Big Five: the 20-item Mini-IPIP (Donnellan et al., 2006) or the longer 50-item IPIP Big-Five Factor Markers (Goldberg, 1992), both from the public-domain International Personality Item Pool. When you take the long version, we use it. Percentiles use approximate published averages. Four temperaments come from Extraversion × emotional sensitivity (Eysenck). The four-letter style comes from our own 28-question preference quiz, scored per letter pair with a clarity score; until you take it, we estimate it from your Big Five (McCrae & Costa, 1989). You can always say a result doesn't fit and pick the one that does: we keep both and show which is which. It is not an official type test, and we are not affiliated with any type-test publisher.
Own questionnaires: attachment (anxiety and avoidance dimensions), nine motivations, care styles, Shadow & Light, body & energy type (Ayurveda-inspired), and Autopilot vs Explorer + social stance (inspired by Dr Jacques Fradin's neurocognitive and behavioural approach, not an official assessment).

How compatibility scores work

Every lens gives two numbers: Harmony (ease and flow) and Spark (energy, challenge, growth). Friction counts toward Spark, not against you. We ran each lens on tens of thousands of random pairs and convert your raw score into a percentile among those pairs, then display it as 45 + 55 × percentile, so the scale runs from 45 to 100 and a typical pair scores about 72. Every pairing has something to offer, so the scale starts at 45.

Lenses are blended into Resonance with weights that depend on the relationship type (romantic, friend, family, colleague) and on confidence (for example, a missing birth time lowers the weight of astrology). The research-backed-only toggle shows a score from the Big Five and attachment lenses alone. There is no “incompatible” band: Kindred Flow, Natural Allies, Complementary Path, Catalyst Bond and Deep Teacher Bond. Every growth edge comes with practices.

Protecting you

We use what's known about shadows and unhealthy patterns to help you notice them, never to label another person, and never against you (no fear-based upsells, no fake urgency). If you feel unsafe in a relationship, please contact local emergency services or a domestic-abuse helpline.