What this calculator does
A Chinese age calculator works out age using the traditional East Asian counting method, which differs from the Western system in two ways: a baby is counted as already 1 year old at birth, rather than 0, and age then increases by one at each Lunar New Year rather than on the person's actual birthday.
This system, sometimes called sui (岁) age, was historically standard across China, Korea and Vietnam and is still used in cultural, astrological and some traditional-medicine contexts today, even though everyday and legal age in those countries now generally follows the Western system. It commonly produces a Chinese age that is one or two years higher than someone's Western age, depending on the time of year.
The formula
Start from 1 at birth. Add one year for every Lunar New Year that has occurred between the birth date and the date being checked. Because the answer depends on whether the birth date fell before or after that year's Lunar New Year, and whether the current year's Lunar New Year has passed yet, both of those are asked directly rather than assumed. Lunar New Year falls on a different date each year, typically between late January and late February, so check the specific date for the years involved if precision matters.
| Term | Meaning |
|---|---|
| Sui age | The traditional East Asian age-counting unit: 1 at birth, then +1 at each Lunar New Year. |
| Lunar New Year | The start of the traditional Chinese lunisolar calendar year, the point at which traditional age increases, falling on a different date each year between late January and late February. |
| Western age | The familiar age system that starts at 0 at birth and increases by one on each birthday, shown alongside for comparison. |
The inputs explained
| Field | What to enter |
|---|---|
| Birth year | The birth year. |
| Was your birthday before that year's Lunar New Year? | Whether the birth date fell before that year's Lunar New Year (relevant because it changes how many Lunar New Years have passed since birth). |
| Current/target year | The year to calculate the Chinese age for, often the current year. |
| Has this year's Lunar New Year already passed? | Whether that target year's Lunar New Year has already happened by the date you are checking. |
When to use it
Understanding a family elder's stated age
Older relatives from China, Korea or Vietnam sometimes give their age using the traditional counting method rather than Western age, which can be confusing if the two systems are not distinguished. Working out both figures side by side clears up the mismatch.
Reading a Korean age reference
Korean age (a closely related counting system) is still widely used in everyday conversation in Korea, even though the country also uses international age officially. Converting between the two avoids misreading someone's stated age.
Checking a birth-year animal or astrological reference
Chinese zodiac and some traditional-medicine age references are tied to the lunisolar calendar and traditional age counting rather than Western birthdays, so getting the traditional age right matters for those contexts.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How Chinese age compares to Western age across a range of birth years
A range of birth years, all evaluated the same way in 2026.
| Birth year | Chinese (East Asian) age | Approximate Western age for comparison |
|---|---|---|
| 2026 | 1 years old | 0 years |
| 2020 | 7 years old | 6 years |
| 2010 | 17 years old | 16 years |
| 2000 | 27 years old | 26 years |
| 1990 | 37 years old | 36 years |
| 1980 | 47 years old | 46 years |
How the Lunar New Year timing changes the result for one birth year
The same birth year and target year, across the four combinations of whether each Lunar New Year had passed.
Questions
Why is Chinese age usually higher than Western age?
Two reasons combine: a baby starts at 1 rather than 0, and the age-up point is the Lunar New Year rather than the birthday. Depending on the time of year, this typically makes Chinese age one or two years higher than Western age.
Is this the same as Korean age?
They are closely related but not identical. Traditional Korean age also starts at 1 at birth, but South Korea officially moved to counting the age-up point at the Western New Year (1 January) for Korean age in casual use, alongside international age for official purposes, rather than the Lunar New Year used in the traditional Chinese system.
Do China, Korea and Vietnam still use this for official purposes?
No. All three now use the Western age system for legal, medical and administrative purposes. Traditional age counting persists mainly in cultural, family and some traditional-medicine or astrological contexts.
Why do I need to know the exact Lunar New Year date?
Because it moves every year, generally falling somewhere between late January and late February, whether a birth date or the current date falls before or after it changes the result by a full year. This calculator asks the question directly rather than guessing, so check the specific Lunar New Year date for the years involved if you need an exact answer.
For an ordinary Western age in years, months and days, see the age calculator. If you only know a birth year and not the full date, the age from birth year calculator gives a Western-age range.