# Zodiac sign calculator by birth date

Find your zodiac Sun sign from your birth date. On cusp dates, add time and place for a precise answer instead of guessing.

Start with your birth date. It’s free and takes a minute.

## Start with your birth data

Choose the city from the results. Date and time stay on your device.

See an example

## Common questions

### Why are my houses different from those on other sites?

Astraluno uses Whole Sign houses; many sites use Placidus. Both are traditional methods. Signs and planets do not change.

### How accurate is the calculation?

Planet positions were checked against NASA JPL Horizons: a maximum gap of 0.34 arcminutes over 310 positions. The Ascendant was checked on 68 cases. We use historical time zones with daylight saving rules.

### Is Astraluno free?

Yes. The calculator and all readings are free, without an account or payment card.

### Can I calculate a chart without my birth time?

Yes. We check the full local day and show possible signs. Without a time, the rising sign and houses are unavailable.

### Are birth details sent to the server?

No. Date and time are processed in the browser. The server receives the city search query and the request for the time-zone file.

## Links

- [See an example](https://astraluno.com/example-birth-chart/)

Canonical: https://astraluno.com/zodiac-sign-calculator/
Last revised: 2026-10-13