A practical guide to a living tradition
Chinese Age Calculator
Enter your Gregorian birth date to compare international age with Chinese nominal age (虚岁, xu sui), counted at Lunar New Year.
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Nominal-age conventions vary by region, family, and context. International age is standard in most official contexts.
How this is calculated
International age counts completed birthdays. Traditional nominal age is the as-of lunar year minus the birth lunar year, plus one. The ages may be equal, or nominal age may be one or two years greater.
Read the calculation methods, ranges & time zones →How to calculate Chinese age
- Enter a Gregorian birth date. If your source gives a lunar date, use the Chinese calendar converter first.
- Choose an as-of date, or leave it blank to use today.
- Compare the two ages and the lunar years shown in the result. This tool uses Lunar New Year as the nominal-age boundary.
Chinese mother age calculator: use a known reference date
To check a mother’s age, enter the mother’s Gregorian birth date in Birth date and the known reference date in As-of date (optional). Leaving the second field blank calculates age today. The same form compares completed Gregorian birthdays with nominal age counted at Lunar New Year; being a mother does not require a different age formula.
Chinese age at time of conception: a recorded date only
If you already have a recorded conception reference date, use that date as the as-of date. The calculator does not infer conception from a due date, pregnancy week or age result, and cannot confirm the medical accuracy of the date supplied. Keep an uncertain date labelled as uncertain rather than treating the age output as confirmation.
For example, a June 15, 2000 birth gives international age 23 and nominal age 24 on February 9, 2024, then nominal age 25 on February 10 while international age remains 23. These are calendar examples, not pregnancy dates. If your question concerns an age-and-month prediction chart, read Chinese Gender Calendar: Lunar Age and the Evidence; an age conversion cannot predict a baby’s sex.
Virtual age, lunar age and actual age
“Chinese virtual age,” “Chinese nominal age,” and “xu sui” refer here to the same count: age one during the birth lunar year, then another year at each Lunar New Year. “Actual age” or international age means completed Gregorian birthdays. The calculator shows both so you can state which number you mean instead of treating them as interchangeable.
To calculate nominal age manually, find the lunar year of the birth date and of the as-of date, subtract the birth lunar year, then add one. For actual age, subtract Gregorian birth years and subtract one more if that year’s birthday has not occurred. Use complete dates for both steps: January 1 does not necessarily belong to the lunar year bearing that Gregorian year number.
Why adding one is not always enough
For someone born on June 15, 2000, the international age on February 9, 2024 is 23 and the nominal age is 24. On February 10, 2024—Lunar New Year—the nominal age becomes 25 while the international age remains 23. The birthday and the lunar-year boundary are separate events.
The two ages can also be equal. Someone born on February 1, 2023 is one by both counts on February 1, 2024: a Gregorian birthday has passed, but both dates still fall in lunar year 2023.
This example follows the convention calculated by this tool. It is not a rule for every family or community. For official forms, use the age convention requested by the relevant organization.
Chinese birth chart with age: what this result supplies
If you are checking a Chinese birth chart with age, first record the original Gregorian birth date, the equivalent lunar date (including any leap month), and the exact as-of date. This tool supplies international age, nominal age, birth lunar year and as-of lunar year. For example, a June 15, 2000 birth checked on February 10, 2024 gives age 23 by birthdays and nominal age 25; the birth lunar year is 2000 and the reference lunar year is 2024.
Age is an annotation to a record, not a substitute for its calendar inputs. A Four Pillars or Ba Zi chart concerns year, month, day and hour, with a declared method for boundaries and birth-time handling. The age result does not calculate those pillars. The heavenly stems and five phases guide explains the year stem, element and polarity; the zodiac finder supplies the animal year under this site’s Lunar New Year convention.
If “birth chart” means an age-and-month baby gender chart, a nominal-age conversion cannot establish a baby’s sex. This page provides the calendar and age reference only; it does not produce a gender prediction. Do not infer conception dates or a full horoscope from the two age numbers.
Prepare a recorded lunar birthday
Before entering an old family record, confirm whether its date is Gregorian or lunar. A lunar record needs the year, month, day and regular/leap designation; convert that date once, then use the resulting Gregorian date here. A leap month repeats a month number, not an entire year, and does not add an extra year to nominal age. Birth and as-of dates must be real dates, with the as-of date on or after birth and no later than today.
Follow the calendar boundary
Explore Lunar New Year traditions and why its date changes, check the festival calendar, or read how regular and leap months differ before converting a recorded birthday.
Frequently asked questions
8 common questions
- What is international age?
- International age is the number of completed years since birth. It increases on your birthday.
- What is traditional nominal age?
- Traditional nominal age, often called xu sui (虚岁), counts the birth year as age one and increases at Lunar New Year. Usage varies by region and family.
- Is Chinese age always international age plus one?
- No. Under the Lunar New Year convention used here, nominal age can equal international age or be one or two years greater. The difference depends on the birth date and the as-of date.
- Is virtual age the same as Chinese lunar age?
- Virtual age is one English label used for nominal age, or xu sui. This calculator starts at one in the birth lunar year and increases at Lunar New Year. Confirm the convention if a family record or form uses another rule.
- Can I use Chinese age for a Chinese birth chart?
- Use the result as an age and lunar-year reference, with a stated as-of date. It does not calculate a complete birth chart. A Four Pillars chart involves year, month, day and hour conventions; age alone cannot supply those inputs or predict a baby’s sex.
- Can I use this as a Chinese mother age calculator?
- Yes, for an age reference: enter the mother’s Gregorian birth date and choose the known date in As-of date (optional). The result compares completed-birthday age with nominal age under this tool’s Lunar New Year convention. It does not assess a pregnancy or predict a baby’s sex.
- Can I calculate Chinese age at the time of conception?
- If you already have a recorded conception reference date, enter it as the as-of date. The calculator counts age on the date you supply; it does not infer conception from a due date, estimate it from a pregnancy week, or confirm the date’s medical accuracy. If the date is unknown, the tool cannot supply it.
- Should I enter a Gregorian or lunar birth date?
- Enter a Gregorian birth date. If you have a Chinese lunar birth date, convert it first using its year, month, day and regular or leap-month designation.