Korean 100-Day & First Birthday Calculator: Baegil and Dol

Korean family milestones

Find your baby’s Baegil and Dol dates

Enter a Gregorian (solar-calendar) birth date to plan two Korean celebrations: Baegil (백일), the baby’s 100th day, and Dol (돌), the first birthday. The calculator shows its counting method instead of hiding a possible one-day difference.

Dates are calendar dates. “Today” uses the date in South Korea (Asia/Seoul), even if you are abroad.

How the dates are counted

This tool counts the birth date as day 1. Baegil therefore lands 99 calendar days after birth. If someone means “100 full days have passed,” that date is one day later; both appear in the result so you can check which convention your family intends. The first birthday is the same month and day in the following Gregorian calendar year.

For example, a baby born on January 1, 2026 reaches the 100th calendar day on April 10, 2026. One hundred elapsed days ends on April 11. Dol is January 1, 2027. Neither a lunar-calendar conversion nor a time-of-birth calculation is performed.

Before you book a celebration

  • Use the calendar birth date your family plans to commemorate. A birth close to midnight may have a different date in another time zone; this tool does not convert time zones.
  • For a February 29 birth, the next year may have no February 29. The result shows both February 28 and March 1 as planning choices instead of imposing one family custom.
  • A family may celebrate on a nearby day. Check the date with relatives and any venue before making a booking.

What are Baegil and Dol?

Baegil marks a baby’s 100th day; Dol marks the first birthday. Korea.net describes both as family milestones and documents clothing and other traditions associated with the 100th day. Those cultural sources explain the occasions; the arithmetic and its day-one convention are stated above so you can verify the result yourself.

Sources checked September 29, 2026. The calculation runs in your browser. This tool does not save the dates you enter.

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