About this tool
This Korean lunar calendar converter changes a solar (Gregorian) date into a lunar date and back again, for any day from 1900 to 2100.
It has three modes. Solar to Lunar shows the lunar year, month and day for a solar date, with the weekday, the ganji year name such as Byeong-O, the zodiac animal, and whether the lunar month has 29 or 30 days.
Lunar to Solar takes a lunar year, month and day, with a leap month checkbox, and returns the solar date.
Lunar Birthday finds the solar date on which your lunar birthday falls in any year you choose, and lists the next five years, which is handy because the date moves every year.
For example, Seollal, the lunar new year, falls on 2026-02-17, and Chuseok 2025 falls on 2025-10-06.
A leap month repeats a month number to keep the lunar calendar aligned with the seasons; 2023 had a leap second month that began on 2023-03-22.
If a lunar month has only 29 days and you enter day 30, the birthday finder uses day 29. Everything runs in your browser using a built-in data table, and nothing you enter is sent to a server.
Data note: the table of month lengths and leap months was generated from astronomical calendar calculations, not copied from an official Korean source.
It agrees with the official Korean lunar calendar on most dates, but because the Korean and Chinese lunar calendars occasionally start a month on different days, a result may be off by one day on rare dates.
For ancestral rites (jesa), weddings, legal documents or other important dates, please confirm with the lunar-solar converter of the Korea Astronomy and Space Science Institute (KASI). Results are for reference only.
How to use
- Choose a mode: Solar to Lunar, Lunar to Solar, or Lunar Birthday.
- Enter the date. For Lunar to Solar, tick the leap month box if it is a leap month.
- Read the converted date together with the weekday, ganji year and zodiac animal.
- In Lunar Birthday mode, enter a year to see this year's solar date and the next five years.
- For important dates such as jesa or weddings, double-check with the Korea Astronomy and Space Science Institute (KASI) converter.