Zodiac Sign Calculator

Your Western (tropical) sun sign is the twelfth of the sky the Sun was in when you were born, measured from the March equinox. The Chinese zodiac follows a 12-year cycle of animals and a 10-year cycle of elements, and the year changes at Chinese New Year, not on 1 January. None of this can predict anything: it’s tradition and fun.

The formula

Star sign = the sign whose dates hold your birthday (with a year: where the Sun really was at your birth time)
Chinese year = birth year, minus 1 if you were born before that year’s Chinese New Year
Animal number = (Chinese year − 4) ÷ 12, take the remainder (0 Rat, 1 Ox, 2 Tiger … 11 Pig)
Element number = (Chinese year − 4) ÷ 10, take the remainder: 0–1 Wood, 2–3 Fire, 4–5 Earth, 6–7 Metal, 8–9 Water
Yin or yang = odd Chinese year is yin, even is yang

Worked example

Born 26 January 1990. 26 January is between 20 January and 18 February, so the star sign is Aquarius: an air sign, fixed mode, ruled by Uranus (Saturn in older astrology). Chinese New Year 1990 was on 27 January, so 26 January was the day before and counts as Chinese year 1989. (1989 − 4) = 1985, and 1985 ÷ 12 = 165 remainder 5, which is the Snake. 1985 ÷ 10 = 198 remainder 5, which is Earth, and 1989 is odd, so yin: an Earth Snake. Born a day later, on 27 January 1990, it would have been a Metal Horse. January’s birthstone is garnet and its flowers are the carnation and snowdrop.

On the cusp, and the exact change

The usual sign dates are a fixed list, but the Sun enters each sign at a different moment each year, so the change day can move by a day, and it depends on your time zone. When you add your birth year, this page works out where the Sun was (at noon on your birthday, or at your birth time in Advanced) using a standard astronomy formula that’s good to about 15 minutes. If the Sun changed sign on your birthday, the note under the result tells you the time, so you can check against your birth time. “On the cusp” here means within 2 days of a change.

Vedic (sidereal) signs

Vedic astrology in India measures signs against the stars instead of the seasons. Over about 2,000 years the two have drifted apart by about 24°, so Vedic sign dates come about 3 weeks later: Aries (Mesha) is roughly 14 April to 14 May, and Capricorn (Makara) starts around 14 January, the day of Makar Sankranti. This page uses the Lahiri value, the most common one.

Chinese zodiac: animals, elements and matches

Elements go in pairs of years: Wood (years ending 4 and 5), Fire (years ending 6 and 7), Earth (years ending 8 and 9), Metal (years ending 0 and 1), Water (years ending 2 and 3). Traditional matches: animals four years apart are a “trine” of best friends; six pairs are “secret friends” (Rat–Ox, Tiger–Pig, Rabbit–Dog, Dragon–Rooster, Snake–Monkey, Horse–Goat); animals six years apart clash. For Western signs, the same element is the easy match, fire goes with air and earth with water, and opposite signs “attract”.

The two-hour birth animal starts with the Rat at 11 pm to 1 am, then Ox 1–3 am, Tiger 3–5 am and so on round to the Pig at 9–11 pm.

Birthstones and birth flowers

Lists vary by country and jeweller. The first stone is the one on the usual modern list. Chinese New Year dates here cover 1900–2060, from published lunar tables, checked against new moons in China time. Birthdays on 29 February count as 28 February in other years, and a half-birthday that falls on a day the month doesn’t have moves to the month’s last day.