Japanese Era Converter (Reiwa, Heisei, Showa ↔ Western Year)

How Japanese era years work

Japan counts years in two ways. Alongside the Western (Gregorian) calendar, official documents use the gengō, or era name, which changes when a new emperor takes the throne. The first year of an era is written 元年 (gannen) rather than "1", and the count starts again from there. So 2019 was both Heisei 31 and Reiwa 1, and 2025 is Reiwa 7.

You will meet era years on residence cards, bank and city office forms, health insurance cards, pension notices, tax documents, product expiry dates and many websites that ask for your date of birth. Forms often abbreviate the era with a single letter: R for Reiwa, H for Heisei, S for Showa, T for Taisho and M for Meiji. "H2.5.10" therefore means 10 May 1990. Some forms have you circle the era name and then write a two-digit year, which is why a Western birth year alone is not enough.

When each era started

To go the other way, subtract the same number: 2025 − 2018 = Reiwa 7, and 1990 − 1988 = Heisei 2. The formulas only work for years that actually belong to that era, which is where most mistakes happen.

Years with two eras, and years that never existed

Whenever the era changed part-way through a year, that Western year contains two era years. 1989 is the classic trap: 1 to 7 January 1989 was Showa 64, and from 8 January it was Heisei 1. Likewise 2019 runs from Heisei 31 until 30 April and is Reiwa 1 from 1 May. If you were born in one of these change-over years (1912, 1926, 1989 or 2019), use the full-date field above so that the converter can pick the right era for your exact birthday.

You may also see era years that never happened. Because the switch to Reiwa was announced only a month in advance, some printed forms, calendars and computer systems carried on counting in Heisei, producing dates such as "Heisei 32" (which would be 2020). The converter tells you when a year is outside its era and shows the Western year it was meant to be, so you can still make sense of the document.

Dates before 1873 are not supported. Until the end of Meiji 5 (1872), Japan followed a lunisolar calendar, so month and day numbers from that time do not match the Western calendar.

Tips for filling in Japanese forms

• Check whether the form wants the era or the Western year. Many newer forms accept either, but older ones print the era names and expect you to circle one.
• Write the year of the era, not your age. A common slip is to write the number of years you have lived.
• On computer forms, Gannen is entered as 1.
• Your residence card and passport use Western dates, so keep the converted date handy when you visit the city office or a bank.

Year chart from 2027 back to 1926

The zodiac animal is shown for the Western year as a whole. Ages assume the birthday in 2026 has already passed; before your birthday, subtract one.

Frequently asked questions

What year is Reiwa 1?

Reiwa 1 is 2019, starting on 1 May 2019. From 1 January to 30 April 2019 it was still Heisei 31.

What does "H" or "S" mean in a Japanese date?

They are abbreviations of the era name: R = Reiwa, H = Heisei, S = Showa, T = Taisho, M = Meiji. For example, S60 is Showa 60, which is 1985.

Did Showa 64 really exist?

Yes, but only for seven days: 1 to 7 January 1989. Heisei began on 8 January 1989.

Is "Gannen" the same as year 1?

Yes. Gannen (元年) is simply the traditional way of writing the first year of an era. Online forms usually expect the number 1.

Last updated: 2026-10-28