Japanese Era (Nengō) Converter

About this calculator

Japan has used the nengō (元号) system for centuries, naming eras after the reigning emperor and counting years from 1 within that era — so 2024 in the Gregorian calendar is Reiwa 6 (令和6年), following Heisei (1989–2019) and Shōwa (1926–1989) before it. Each era begins on the date of imperial succession, so the conversion depends not just on the year but sometimes on the month and day too, especially for the first and last year of an era.

This calculator takes a Gregorian date and returns the corresponding Japanese era name and era year. Genealogists and family historians researching Japanese records, translators and administrative staff processing Japanese official documents such as koseki (family registers), driver's licenses, and pension paperwork — which are commonly dated in the era format rather than the Gregorian year — rely on this conversion to read and fill out such documents correctly.