Sun Sign Calculator

You belong to whichever sign the sun was actually in on your birth date. There is no shared 'cusp sign' in tropical Western astrology — the boundaries are firm. Dates near the edge can shift by a day depending on the year because the sun doesn't move on a perfect 24-hour schedule, so if you were born within a day of a cutoff and want to be certain, check your exact birth time against an ephemeris.

Tropical (Western) astrology fixes the signs to the seasons — Aries always starts at the spring equinox. Sidereal (Vedic) astrology fixes the signs to the actual constellations, which have drifted about 24 degrees due to precession of the equinoxes. This calculator uses the tropical zodiac, which is the standard for Western astrology.

The sun changes signs at a specific moment, not at midnight. If you were born within ~24 hours of a sign change, the exact time and time zone of your birth determines your sign. Calculators that use only the date assume the sun has moved by the end of the day — accurate for the vast majority of people, but for cusp births you may want a precise chart.

Yes — 'zodiac sign,' 'star sign,' and 'sun sign' all refer to the same thing in casual use: where the sun was at your birth. Astrologers also speak of moon signs and rising signs, which together with the sun make up your 'big three.'

No. The sun sign is the most visible part of your chart — your core identity and ego — but a full natal chart has ten planets plus the angles (rising, midheaven), each in its own sign and house. Two people with the same sun sign can be wildly different once the rest of the chart is read.