Japanese Era Converter (Reiwa, Heisei, Shōwa)

Convert between Gregorian years and Japanese eras — Reiwa, Heisei, Shōwa, Taishō, Meiji — and see the current Reiwa year at a glance.

How to use

  1. Enter a Gregorian year, or an era name plus its year number.
  2. Get the instant conversion to the other format.

Quick math: Reiwa year = Gregorian year − 2018, Heisei year = Gregorian year − 1988, Shōwa year = Gregorian year − 1925.

In depth

Japanese era names restart the year count

Japan uses era names (gengō) alongside the Gregorian calendar. A new era begins when an emperor accedes, and that year is year one (gannen).

The modern eras: Meiji (1868–1912) · Taishō (1912–1926) · Shōwa (1926–1989) · Heisei (1989–2019) · Reiwa (2019– ).

The 1979 Era Name Act fixed one era per emperor. Before that, eras were changed mid-reign after disasters or auspicious events.

Where conversion goes wrong

Reiwa converts as Gregorian = Reiwa + 2018. Reiwa 6 is 2024.

Heisei converts as Gregorian = Heisei + 1988. Heisei 31 is 2019.

Shōwa converts as Gregorian = Shōwa + 1925. Shōwa 64 is 1989.

Transition years contain two eras. 2019 was Heisei 31 through 30 April and Reiwa 1 from 1 May. You need the date, not just the year.

1989 works the same way — Shōwa 64 until 7 January, Heisei 1 from the 8th. Which means Shōwa 64 lasted only a week.

Where you encounter them

Official documents — Japanese government paperwork overwhelmingly uses era years. Visa applications, residence cards, resident records.

Driving licences and passports — validity dates in era years.

Contracts and property registration.

Medical and academic records — dates of birth frequently recorded in era years.

Filling in a Japanese form and needing to write your date of birth as a Shōwa or Heisei year is a genuinely common situation.

Writing year one

The first year of an era is written 元年 (gannen) rather than "1". It is 令和元年, not 令和1年.

Systems generally accept 1 as input, but handwritten official documents use 元年.

This mismatch causes real data-processing errors, in systems that cannot parse 元 as a number.

Abbreviations use the Roman initial — M · T · S · H · R. A Japanese document reading "S45.3.2" means 2 March, Shōwa 45.

The 2019 transition

The change to Reiwa was called Japan's Y2K. Countless systems handle era years, and the new era name was announced only a month beforehand, on 1 April 2019.

Until then, developers had to prepare systems for an era whose name they did not know.

There was also the risk that the new initial would collide with an existing abbreviation. Reiwa (R) fortunately did not.

The episode revived arguments for using only Gregorian years, but era names are bound up with cultural identity and remain in use.

How conversion works here

Using the browser's Intl Japanese calendar. Transition dates are in the data, so overlapping years are split correctly by date.

No external API is called and nothing is transmitted.

Very old browsers predating 2019 may not know Reiwa. Update if the output looks wrong.

FAQ

What era is it now?

Japan has been in the Reiwa (令和) era since May 2019.

How does the conversion work?

Each era's start year plus the era year gives the Gregorian year; eras change mid-year, so a Gregorian year can span two eras.

Why can one Gregorian year span two Japanese eras?

Eras change on the exact day of an imperial succession, not on January 1, so the calendar year the change happens in contains dates from both the old and new era.

Method and sources

What this tool bases its numbers on, and how far those numbers go.

What this tool is
A year-number conversion. It converts era years, not dates — for a transition year the era depends on the exact day, and that day is not something this tool asks you for.
Formula
Gregorian = era year + the era's base: Reiwa + 2018, Heisei + 1988, Shōwa + 1925, Taishō + 1911, Meiji + 1867. The inverse subtracts the same base. Era year 1 is «gannen», the year of accession.
Worked example
Reiwa 8 = 8 + 2018 = 2026. Going the other way, 1989 is both Shōwa 64 (to 7 January) and Heisei 1 (from 8 January).
Limitations
  • Transition years belong to two eras. 2019 is Heisei 31 up to 30 April and Reiwa 1 from 1 May; 1989 is Shōwa 64 for its first week. A year alone cannot resolve which.
  • Only the five modern eras are covered — Meiji onward. Pre-1868 eras changed mid-reign after disasters or auspicious signs and are not convertible by a fixed offset.
  • Era year 1 is a partial year. Shōwa 64 lasted seven days and Heisei 31 four months, so «one era year» is not one calendar year at the boundaries.
  • It does not convert Japanese fiscal years, which run April to March and are cited in era years in official statistics.
  • The era names are those used in Japan. Other calendars that also restart year counts — the Republic of China calendar, the Juche calendar — use different bases and are not handled.
Sources
Effective date
Last reviewed

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