Korean Lunar-Solar Calendar Converter

How to Use

1. Choose a direction: Solar → Lunar or Lunar → Solar.
2. Enter the date. For Lunar → Solar, also check "Intercalary month" if the date falls in a leap month (윤달).
3. The converted date and the sexagenary cycle (Gapja) name are calculated instantly.

How the Conversion Works

The traditional Korean lunar calendar (음력) follows the standard published by KASI (Korea Astronomy and Space Science Institute). Unlike the solar calendar, lunar months can include an extra "intercalary" or leap month (윤달) roughly every 2-3 years to keep the lunar calendar aligned with the solar year — so the same lunar month/day can occur twice in a year, once as a regular month and once as the leap month. The result also includes the Gapja (육십갑자), a traditional 60-term cycle combining 10 "heavenly stems" and 12 "earthly branches" used to name years, months, and days.

Common Uses

• Finding the solar calendar date for a traditional holiday, birthday, or memorial day (제사) that is tracked by the lunar calendar.
• Converting a historical or family record date between lunar and solar calendars.
• Looking up the Gapja (sexagenary) name of a birth year, often used in traditional fortune-telling (사주) or naming customs.

Supports dates from 1000-01-01 to 2050-11-18 on the lunar calendar.