Zodiac sign calculator by birth date

Find which tropical Sun sign may correspond to your date of birth. A date close to a sign change can have more than one possible result when the birth time and time zone are unknown.

How the calculation works

We calculate the Sun’s geocentric tropical longitude using Astronomy Engine. The zodiac is divided into twelve 30-degree sectors, beginning with Aries. For an unknown time zone, a civil date can correspond to instants from 14 hours before UTC midnight to 36 hours after it. The calculator checks that conservative interval and shows all Sun signs it encounters. Near a boundary, an exact birth time and historical time zone are required to choose between them.

What this result does not mean

A Sun sign is not a complete birth chart. This tool does not calculate the Moon, the ascendant or houses, and it does not predict events. Tropical signs are coordinate sectors, not the modern astronomical constellations. Use the result as a symbolic reference.

Can two calculators give different results?

Yes. Different inputs, time zones or tropical versus sidereal settings can change the result. On a boundary date, check the actual birth instant rather than assuming a fixed calendar cutoff.

Related reading

Explore your Sun, Moon and rising sign

Calculate your tropical Sun sign, Moon sign and ascendant together from the same birth details. See the degrees and the UTC instant used, so you can compare the calculation rather than just a label.