How is the Japanese era year calculated?

Each modern era begins on an exact Gregorian date — Reiwa on 1 May 2019, Heisei on 8 January 1989, Shōwa on 25 December 1926, Taishō on 30 July 1912 and Meiji on 23 October 1868. The era year equals the Gregorian year minus the era's start year plus one, so the first year of an era is year 1 (Gannen / 元年).

How accurate is the conversion?

It is exact for the modern Meiji-to-Reiwa eras, which each have a fixed Gregorian start date. The tool finds the latest era beginning on or before your date, so transition days are handled correctly. Dates before the Meiji era (1868) are not covered.

Is my date sent anywhere?

No. The converter is privacy-first — all processing happens locally in your browser and no date ever leaves your device.

Japanese Era Converter (Gengō / 和暦)

Japanese era converter

Convert between Gregorian dates and the Japanese era (Gengō / 元号) system used in wareki (和暦) dates. The converter covers the modern eras — Reiwa, Heisei, Shōwa, Taishō and Meiji — each of which begins on an exact Gregorian date. The era year is the Gregorian year minus the era’s start year plus one, so the first year of an era is shown as Gannen (元年).

It is privacy-first: every calculation happens locally in your browser and nothing is ever sent anywhere.