Enter a birthdate to get Chinese nominal age (xu sui), Western age, zodiac, and lunar birth year. Answer the "how old are you?" question the right way.
Learn how Chinese age works ↓Enter a birthdate to see nominal age, zodiac, and a 10-year forecast.
Chinese nominal age, called xu sui, counts you as one year old on the day you are born and adds a year every Chinese New Year. That makes nominal age one to two years higher than Western age, most visibly right after the Lunar New Year.
Formula: nominal age = current year − lunar birth year + 1. The trick is the lunar birth year. If you are born before Chinese New Year, your lunar year is one less than the Western year. A January 15, 1990 birthday belongs to lunar year 1989, because the 1990 Lunar New Year fell on January 27.
Western age ticks up on your birthday. Nominal age ticks up on Lunar New Year, and you start at one on the day you are born. As a result, nominal age runs two years higher than Western age if your birthday falls before Chinese New Year, and one year higher if after.
Western paperwork, passports, and legal documents use Western age. Traditional contexts (Chinese New Year greetings, matchmaking, feng shui, astrology readings) use nominal age. Chinese-speaking communities carry both numbers in parallel.
Chinese New Year lands somewhere between January 21 and February 20, varying each year. A birthday in late January or early February needs the actual Lunar New Year date to confirm the lunar birth year. Premature babies count by actual birth date, not due date: a baby due in mid-February but born in late January belongs to the previous lunar year, with a different zodiac sign.
A person born on March 15, 1990 is past the 1990 Lunar New Year (January 27), so the lunar birth year is 1990, which is a Year of the Horse (庚午). In 2026 their nominal age is 2026 − 1990 + 1 = 37; their Western age is 2026 − 1990 = 36.
Close but not identical. Korean age adds a year on January 1 (Western New Year), while Chinese nominal age adds a year on Lunar New Year. For most of the year the numbers match, but they can differ by one around January.
Nominal age is anchored to Lunar New Year. Someone born before Lunar New Year has a Western birth year one ahead of their lunar birth year. For example, someone born January 15, 1990 has a Western year of 1990 but a lunar year of 1989 (己巳, Year of the Snake). Using the Western year directly would give the wrong zodiac and age. The lunar birth year avoids these boundary errors.
Births on Lunar New Year's Day belong to the new lunar year. The calculator uses the lunar calendar under the hood, so you do not have to look up the exact New Year date yourself.
Everyday Chinese-speaking custom marks the zodiac by Lunar New Year. Chinese astrology (BaZi) traditionally marks it by Li Chun (around February 4). This tool uses the lunar year boundary, aligned with nominal age. For the Li Chun zodiac used in BaZi readings, use the BaZi calculator.
Yes. BaZi major cycles (大運), Ziwei annual forecasts, and auspicious-date calculations are counted by nominal age. Knowing your nominal age lets you map directly onto the cycle start ages and yearly markers in a reading.
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