Lunar birthday calculator: your birthday in the Chinese calendar
This lunar birthday calculator converts any Western (Gregorian) birthday into the Chinese lunar calendar. Enter the date you were born and it gives your Chinese lunar birthday: the lunar month and day you were born on, written the traditional way (for example 正月十五, the fifteenth of the first month, which is the Lantern Festival), together with the zodiac animal and element of that lunar year. In China, many families still mark birthdays by the lunar calendar, so the date moves every year on the Western calendar. The conversion uses the astronomical lunar calendar tables, the same ones printed in Chinese almanacs.
- Year
- Element
- Yin or yang
- Earthly branch
- Hours of the animal
- Lunar birthday
- Best company
- Your next year
Make the poster
Your animal in ink, the lunar date, and your name. Add a Chinese name and it is set as a round seal.
How the Chinese lunar calendar is built
The Chinese calendar (农历, nónglì) is lunisolar: its months follow the moon, and its years are kept in step with the sun. Each month begins on the day of a new moon, and because the moon takes about 29.5 days to come round, a month has either 29 or 30 days. The first day of the month is always a new moon and the fifteenth is close to the full moon, which is why so many festivals fall on the fifteenth.
Twelve such months make about 354 days, eleven short of a solar year. To stop the months drifting through the seasons, a thirteenth, leap month (闰月, rùnyuè) is added roughly every two or three years. It goes where a month contains none of the twelve principal solar terms, and it repeats the number of the month before it: lunar 2025 had two sixth months, the second of them, 闰六月, running from 25 July to 22 August 2025. Someone born in a leap month usually celebrates in the ordinary month of the same number, since most years have no leap month to match.
How a lunar date is written
A lunar date is written month first, then day, in Chinese numerals with a few names of their own. The first month is 正月 (zhēngyuè), not 一月; the eleventh is often called 冬月 (dōngyuè), the winter month; the twelfth is 腊月 (làyuè). The days have fixed forms:
| Days | Written | Read |
|---|---|---|
| 1–10 | 初一 … 初十 | chūyī … chūshí |
| 11–19 | 十一 … 十九 | shíyī … shíjiǔ |
| 20 | 二十 | èrshí |
| 21–29 | 廿一 … 廿九 | niànyī … niànjiǔ |
| 30 | 三十 | sānshí |
Born 3 October 1990. That day was the fifteenth of the eighth lunar month, the Mid-Autumn Festival, in the year of the Metal Horse. The lunar birthday then lands on a different Western date each year: 25 September in 2026, 15 September in 2027. A child born on the festival night shares the mooncakes with everyone, every year.
The animal and element of the year come from the same calculation; the Chinese zodiac calculator explains why they can differ from a year-only table.
Festivals that fall on lunar dates
Every traditional Chinese festival is fixed to a lunar date, so its Western date moves each year. If your lunar birthday matches one of these, the calculator says so.
| Festival | Lunar date | In 2027 |
|---|---|---|
| New Year's Eve, 除夕 (chúxī) | 腊月 last day | 5 February |
| Spring Festival, 春节 (chūnjié) | 正月初一 | 6 February |
| Lantern Festival, 元宵节 (yuánxiāojié) | 正月十五 | 20 February |
| Dragon Boat Festival, 端午节 (duānwǔjié) | 五月初五 | 9 June |
| Qixi, 七夕 (qīxī) | 七月初七 | 8 August |
| Mid-Autumn Festival, 中秋节 (zhōngqiūjié) | 八月十五 | 15 September |
| Double Ninth, 重阳节 (chóngyángjié) | 九月初九 | 8 October |
New Year's Eve is the last day of 腊月, whichever that is: when the month has 29 days, as it does before Chinese New Year 2027, the eve is 腊月廿九. It is the night the couplets go up.
Why older relatives give their birthday by the lunar date
Many Chinese grandparents know their birthday only as a lunar date because that was the calendar their families lived by. Farming, festivals, weddings and birthdays were reckoned on it, and a mother remembered a birth as "the third of the eighth month", not by a Western date. So when a grandmother says her birthday is 八月初三 (bāyuè chūsān), she means a day that moves each autumn.
Big birthdays for elders, the sixtieth, seventieth and eightieth, are still often held on the lunar date, and traditional age-counting (虚岁, xūsuì) adds a year at New Year, not on the birthday. If you want to call on the right day, convert the date once here, then look up its Western date each year; printed Chinese calendars show both.
How it works
Enter the day, month and year you were born.
Read the "Lunar birthday" line: month and day in the Chinese calendar, and any festival that falls on it.
Add your name and make a poster with the lunar date and your zodiac animal in ink.
Questions
What is my Chinese lunar birthday?
Your Chinese lunar birthday is the month and day of the Chinese lunar calendar on which you were born. It is written month first, for example 八月初三, the third day of the eighth month. Because lunar months do not line up with Western ones, it falls on a different Western date every year.
How do I convert my birthday to the Chinese lunar calendar?
Enter the day, month and year of your Western birthday in the calculator. There is no simple formula: each lunar month starts on an astronomical new moon and leap months are added by the solar terms, so the conversion is read from calendar tables. The calculator does this for any date from 1900 to 2100.
Why does my lunar birthday change every year?
Your lunar birthday changes date because a lunar month is 29 or 30 days, so twelve of them make only about 354 days. The lunar date slips about eleven days earlier each Western year until a leap month pushes it back, which is why the same lunar birthday can move by several weeks from one year to the next.
When is my lunar birthday this year?
Convert your birth date once to find its lunar month and day, then look that lunar date up in the current year's calendar. For example, 八月十五 fell on 25 September in 2026 and falls on 15 September in 2027. Chinese wall calendars and phone calendars with the lunar calendar switched on show both dates side by side.
What if I was born in a leap month?
A leap month repeats the number of the month before it, so a birthday in 闰六月 is in the second sixth month of that year. Most years have no leap sixth month, so people born in one usually celebrate in the ordinary sixth month on the same day. The calculator writes such a date with 闰 in front, as in 闰六月初八.
What is 正月 and what is 腊月?
正月 (zhēngyuè) is the first lunar month, which begins on Chinese New Year's Day; 正月初一 is New Year's Day and 正月十五 the Lantern Festival. 腊月 (làyuè) is the twelfth and last month, whose final day is New Year's Eve. The eleventh month is often called 冬月 (dōngyuè).
What does 廿 mean in a lunar date?
廿 (niàn) means twenty and is used for the days from 21 to 29 of a lunar month: 廿一 is the 21st, 廿九 the 29th. The 20th itself is written 二十 and the 30th 三十. Days 1 to 10 take the prefix 初 (chū), as in 初一 and 初十, so a day number never looks like a month number.
Does my lunar birthday change my Chinese zodiac animal?
It can, if you were born in January or February. The zodiac year begins at Chinese New Year, not on 1 January, so a birthday before New Year belongs to the previous lunar year and its animal. The calculator shows the animal of the lunar year you were actually born in.
How accurate is the conversion?
The conversion follows the astronomical new moons and solar terms that define the Chinese calendar, using the same calendar tables printed in Chinese almanacs, and covers every date from 1900 to 2100. Month boundaries are reckoned on China time, so a birth abroad close to midnight on a new-moon day is worth checking against a printed calendar.
Read more
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