Introduction: "Wait, what year is it in Reiwa?"

When filling out official documents or resumes in Japan, do you ever stop and think, "What year of Heisei did I graduate?" or "What is that in the Western calendar?"

In Japanese government offices and business scenarios, both the traditional "Japanese Era Name" (Gengo/Wareki) and the "Western Calendar" (Seireki) are mixed everywhere. To smoothly process paperwork and avoid confusion, knowing how to quickly convert between the two is an invaluable skill.

In this article, we'll guide you through the simple conversion rules for Reiwa, Heisei, and Showa into the Western calendar, and provide a handy Quick Reference Chart so you never have to do complex mental math again.

1. The Magic Numbers for Era Conversion

Even if you don't have a reference chart, there are easy formulas you can do in your head. Just remember the three "magic numbers" for Reiwa, Heisei, and Showa.

【Reiwa】 Era Rule: The Magic Number is "018"

Japanese Era to Western: Reiwa Year + 2018 = Western Year
- Example: Reiwa 8 + 2018 = 2026
Western to Japanese Era: Last 2 digits of Western Year - 18 = Reiwa Year
- Example: 2026 → 26 - 18 = Reiwa 8
Mnemonic for Japanese speakers: Rei (0) Wa (18).

【Heisei】 Era Rule: The Magic Number is "1988"

Japanese Era to Western: Heisei Year + 1988 = Western Year
- Example: Heisei 10 + 1988 = 1998
Western to Japanese Era: Western Year - 1988 = Heisei Year
- Example: 1998 - 1988 = Heisei 10
Note: Heisei 1 was 1989, making 1988 the "base year 0".

【Showa】 Era Rule: The Magic Number is "1925" or "25"

Japanese Era to Western: Showa Year + 1925 = Western Year
- Example: Showa 60 + 1925 = 1985
Western to Japanese Era: Last 2 digits of Western Year - 25 = Showa Year
- Example: 1985 → 85 - 25 = Showa 60

2. Quick Reference Chart for Major Years

If calculating is too tedious, here is a quick reference table for the most commonly referenced birth years for resumes and official paperwork.

Western Year	Japanese Era	Age of someone born this year (as of 2026)
2026	Reiwa 8	0 yrs
2020	Reiwa 2	6 yrs
2019	Heisei 31 / Reiwa 1 (Gannen)	7 yrs
2010	Heisei 22	16 yrs
2000	Heisei 12	26 yrs
1990	Heisei 2	36 yrs
1989	Showa 64 / Heisei 1 (Gannen)	37 yrs
1980	Showa 55	46 yrs
1970	Showa 45	56 yrs
1960	Showa 35	66 yrs
1950	Showa 25	76 yrs

Note: Extract ages will vary depending on whether the person has had their birthday yet this year. For calculating educational histories (entrance/graduation years), see the next section for an automated approach.

3. The Savior of Resume Writing: Utilize Web Tools

"It's such a pain figuring out what year I entered high school and graduated university just from my birthdate..." "I took a gap year, so the standard reference charts are useless to me."

When filling out your resume's educational or professional history, calculating the years wrong can leave a terrible impression. When in doubt, automated tools are the safest and fastest way.

By using the tool below, you simply enter your birthdate, and it automatically generates a complete timeline of your life—including the exact years you entered and graduated from elementary school through university, displaying both the Western and Japanese Era formats simultaneously.

Japanese Era & Age ChartConvert dates between Western years and Japanese Eras instantly.

Furthermore, if you need to calculate exactly how many days have passed from a specific date in history until today, the tool below is another excellent utility to keep bookmarked.

Date & Days CalculatorCalculate the exact number of days between dates or add days to a date.

Frequently Asked Questions (FAQ)

Q1. Should I use Western years or Japanese Eras on my resume?

A1. Either is perfectly acceptable, but consistency is critical. Don't write your education in "Heisei" and your job experience in "2020". Note that foreign-affiliated companies and modern IT startups predominantly prefer the Western calendar (Seireki).

Q2. Is it "Reiwa 1" or "Reiwa Gannen"?

A2. On official documents and resumes, the first year of any era should ALWAYS be written as "Gannen" (元年) rather than "1 Year" (1年). The same applies to "Heisei Gannen".

Q3. What is the difference between Showa 64 and Heisei Gannen?

A3. 1989 is split. January 1st to January 7th of 1989 falls under "Showa 64". From January 8th onwards, the era officially changed to "Heisei Gannen" (Heisei 1). Because Japanese school years start in April and end in March, school entrance/graduation events in 1989 are almost always recorded as "Heisei Gannen".

Q4. Are there any other eras I need to know for business?

A4. For most working professionals, Showa, Heisei, and Reiwa are the only ones you'll encounter. Before Showa was "Taisho" (1912-1926) and "Meiji" (1868-1912). You likely won't see these unless you are dealing with very old property documents or historical archives.

Q5. What date should I put at the very top of my resume where it asks for the 'Submission Date'?

A5. Write the exact date you intend to mail the envelope, or the exact date of your interview if you are handing it directly. Make sure this date uses the same format (Western or Japanese Era) as the rest of your resume.

Conclusion: Stop Struggling with Year Conversions!

By memorizing simple magic numbers like "add 2018 for Reiwa" or "subtract 1988 for Heisei", you can do on-the-fly conversions right in your head.

However, when you are preparing a resume for a job hunt and absolutely cannot afford a typo, or when you need to calculate multiple dates spanning different eras, the smartest move is to rely on automated tools.

Bookmark the tool below to finish tedious paperwork in seconds, giving yourself more time to prepare for your actual interviews!