More curiosity.
Fewer fixed answers.

A language for reflection

We use astrological archetypes to offer a different angle on familiar situations: making plans, asking for support, or disagreeing with someone you care about. A useful reading can help you find a question you had not thought to ask.

Astrology is not a scientifically validated way to measure personality or predict a relationship. Keep what helps you reflect. Leave what does not fit.

What the compatibility score means

The Sun-sign score is an editorial model based on traditional associations between the four elements and three modalities. It describes relative ease within that model, on a scale of 0 to 100. It is not a percentage chance of success, a psychological test, or advice about who to date.

The supplied scoring model starts with an element-pair value: fire–air 88, earth–water 86, same-element pairs 77–80, and other pairs 58–64. Modality combinations adjust that base by a few points. The original model also handles same-sign pairs separately. Both orders of a pairing return the same score.

We preserve these scores from the project’s original model and use original reflection prompts to put them in context. A lower score is an invitation to talk about differences. Your actual relationship is not being measured.

Modality adjustments

After the element-pair base value, the model applies these adjustments. The order of the two signs does not matter.

Identical signs receive another +4. The original formula caps the final score between 45 and 97. The written label uses three bands: 85 and above, 70–84, and below 70. These boundaries are editorial choices, not measured differences in relationship outcomes.

What the birth details add

If you choose to add accurate birth details, the calculator uses Astronomy Engine for tropical Sun and geocentric Moon positions. Rising signs are approximated from the local sidereal time, latitude, and the horizon’s intersection with the ecliptic. Luxon interprets the city’s historical time zone.

Precise birth times matter near sign boundaries. The current tool supports a searchable list of over 34,000 places and dates from 1900. Rising-sign calculations are limited to latitudes from 65° south to 65° north. The Sun-sign finder can also work from a date alone and supports listed cities at higher latitudes for its precise lookup. It rejects nonexistent or ambiguous local times during clock changes rather than silently guessing. This is a focused placement comparison, not a complete synastry chart.

For the underlying astronomical calculations, see the Astronomy Engine documentation.

Explore the method in more detail

Read the full compatibility chart and worked examples, compare Sun, Moon and Rising signs, and learn how our content is made. Astrunara is the publishing brand; this version has not had an independent expert review.

Your details stay with you

Readings run in your browser. We do not ask for an email address to show a result, and the calculator does not save birth details. Learn more on our privacy page.