In the traditional Chinese count, 虚岁 (xūsuì), a baby is one year old on the day it is born, and everyone gains a year together at Lunar New Year rather than on their own birthday. The everyday count used on identity cards and forms, 周岁 or 实岁, starts at zero and goes up on each birthday. So 虚岁 is usually one or two years higher, and which of the two depends on a single question: which came more recently, your last birthday or the last Lunar New Year?
- If your birthday came more recently, 虚岁 is one year more than your age.
- If Lunar New Year came more recently — New Year has passed and your birthday has not yet arrived — 虚岁 is two years more.
This guide shows how to work out 虚岁 by hand, measures how much of each year the gap is two, explains the few days a year when it is neither one nor two, and describes where the count is still used — including in the age printed on a Malaysian Chinese death notice. Our Chinese age calculator does the arithmetic for any date.
Working it out by hand
Your 虚岁 is the current Chinese year minus the Chinese year you were born in, plus one.
The main complication is finding the right Chinese birth year. The Chinese year starts at Lunar New Year, which falls between 21 January and 20 February, so anyone born in January or early February may belong to the previous Chinese year.
Example one. Born 15 August 1990. Lunar New Year 1990 fell on 27 January, so the birth is in the Chinese year that began in 1990. On 21 September 2026, the current Chinese year began on 17 February 2026. So 虚岁 is 2026 − 1990 + 1 = 37. The Western age is 36, and the birthday is the more recent event, so the gap is one.
Example two. Born 10 January 1991. Lunar New Year 1991 was not until 15 February, so this birth belongs to the Chinese year that began in 1990 — the Year of the Horse, not the Goat. On 21 September 2026, 虚岁 is again 2026 − 1990 + 1 = 37, while the Western age is 35. Lunar New Year came after the last birthday, so the gap is two.
Example three. Born 28 January 2025, the last day of the Year of the Dragon. The next day was Lunar New Year, and the baby turned 2 — at one day old. One year for being born, one for the new year.
How much of the year the gap is two
How long the gap stays at two years depends almost entirely on your birthday. The table below was produced by counting day by day from 2000 to 2039, using the actual date of Lunar New Year in each of those years.
| Birthday | Share of the year when 虚岁 is two more |
|---|---|
| 1 January | 91% |
| 1 March | 7% |
| 1 April | 15% |
| 1 June | 32% |
| 1 September | 57% |
| 31 December | 90% |
Someone born in early March, just after New Year, will be only one year ahead for most of the year. Someone born in late December will be two years ahead for nearly as long. On average, across all birthdays, the gap is two on almost exactly half the days of the year.
The days when it is neither
The rule has an edge that most explanations leave out. Lunar New Year moves by up to a month from year to year, and a birthday in late January or February can land on either side of it. When a birthday that came after New Year in the birth year comes before New Year in the current year, there are a few days when the person has had one more birthday than New Years, and 虚岁 equals their Western age.
Someone born on 16 February 1980, for example, will be 46 by both counts on 16 February 2026. Their birthday has arrived, but that year's New Year is still a day away. The opposite swap gives a gap of three. Someone born on 27 January 1980 is 47 by the Western count and 50 by 虚岁 on 26 January 2028, when New Year has come early and their birthday is a day off.
A day-by-day count for every birth date from 1980 to 1999, across the years 2026 to 2030, finds that each of these events happens on roughly one day in four thousand. They are rare, but a calculator working from the actual dates will catch them.
Where the count is still used
Legal age uses the Western count almost everywhere. Mainland China's Civil Code sets adulthood at eighteen 周岁, full years. The traditional count survives in custom.
Milestone birthdays. Longevity celebrations (做寿) have traditionally followed 虚岁, which is why a family's "sixtieth" often falls when the person is 58 or 59 by the Western count.
Death notices. In Malaysia, the age printed on a Chinese obituary (讣告), introduced with 享寿 or 享年, is often larger again, and by custom rather than arithmetic. A common practice adds three years, one each for heaven, earth and humanity (天地人). Some families in the south add a fourth year for a woman, in recognition of childbearing. Hokkien families may add one more to avoid an age ending in nine. Another form, 积闰, adds a year for accumulated leap months — a person of sixty has lived through about twenty-two of them. These additions are usually made to the real age, not to 虚岁, and they vary by family and community. When a notice gives an age several years higher than the date of birth suggests, this is usually why.
The zodiac. The zodiac animal, and the practice of checking whether one's sign is in conflict with the year (犯太岁), follow the Chinese year of birth. The same question as above applies: someone born in January 1991 is a Horse, not a Goat. Some almanac traditions mark the zodiac year from 立春, the start of spring around 4 February, rather than from Lunar New Year; sources differ, and our calculator uses Lunar New Year.
Elsewhere in Asia. Vietnam has a similar count, tuổi mụ, which goes up at the lunar new year, Tết, and is used alongside the Western one. South Korea's traditional count went up on 1 January rather than at the lunar new year; since 28 June 2023 Korean law and official documents use the Western count, with a "year age" kept for some purposes such as school entry and military service.
How the figures were produced
The rule and its terms are from standard dictionary definitions of 虚岁 and 周岁. Lunar New Year dates are from an open-source implementation of the Chinese calendar, checked against published dates for 2023 to 2027. The worked examples and the table were computed from those dates on 21 September 2026: the share of the year was counted day by day for each birthday across 2000 to 2039, and the rare zero and three gaps by checking every day of 2026 to 2030 for every birth date from 1980 to 1999.
The obituary customs are from a Malaysian funeral operator's published explanation and from a 2017 master's thesis on Hakka funeral practice in Kampar, Perak, at Universiti Tunku Abdul Rahman; practice varies and these sources describe common forms rather than a rule. The Civil Code text is from the published code, and the Korean change from the Korean government's announcement of it.
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