Japanese Era Converter (Wareki ↔ Gregorian) & Age Calculator
Japan counts years by era names (gengō) such as Reiwa (令和) — Reiwa 8 is 2026. Convert any Japanese era year or date to the Western calendar and back, from Taika (645) to Reiwa, see what happened that year, and calculate age from a date of birth. Historical event notes and names are in Japanese.
Japanese era → Western year
Western year → Japanese era
Covers Taika (645) to Reiwa. In a year when the era changed, both era names are shown. For BC years, enter a negative number such as -300 (for periods without era names, the historical period is shown).
Convert a full dateEnter either a Japanese era date or a Western date
With the month and day, the era is exact even in a changeover year (up to Jan 7, 1989 is Shōwa 64; from Jan 8 it is Heisei 1). Romaji (Showa 64.1.5), abbreviations (H17.8.20) and Japanese (平成17年8月20日, full-width digits) all work. You can also pick a date with “📅 Calendar”.
List of Japanese eras
| Era | Start | End | Conversion |
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Enter a date of birth
Normally age goes up on the birthday. Under Japanese law it goes up the day before — tick this when the exact day matters, such as school-year cutoffs or age-based eligibility in Japan.
Calculate ages in bulkOne person per line
You can paste columns straight from a spreadsheet. Lines that can't be read are shown in red with the reason.
Results
Find the birth year from an ageWorks back from “now N years old”
The birth year differs by one depending on whether the birthday has passed, so both are shown.
In Japan, people born Jan 1–Apr 1 (hayaumare) are in the school year above others born that year, which changes the “life milestones” shown.
What this tool does
HANEAge is a free Japanese era converter and age calculator. Japanese documents — residence cards, contracts, tax and city-hall forms — often write years in the Japanese era system (wareki), e.g. 令和8年 = Reiwa 8 = 2026. This tool converts them both ways. No installation or sign-up is needed, and everything is calculated in your browser — dates you enter are never sent to or stored on a server.
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📅Japanese era ↔ Western calendar
Covers about 250 eras from Taika (645) to Reiwa, showing both Northern and Southern Court eras for the Nanboku-chō period. Kanji numerals (天正十年), abbreviations (S64.1.5) and romaji (Showa 64) are all understood.
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🎂Instant age calculation
Enter a birth date in either calendar. See the age, the traditional kazoe age and days since birth, with an option for Japan's legal counting (age goes up the day before the birthday).
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📋Any number at once
Every tab has a “Bulk” mode. Paste one item per line to list era ↔ Western conversions (optionally with weekdays), ages and kazoe ages, or birth years from ages. Copy the results for a spreadsheet or save them as CSV.
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🔄Birth year from age
Find the birth year of someone who is, say, 40 now — in both Western and Japanese era years, for both before and after their birthday — along with topics from that year.
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💬Generation topics (Japan)
See which major events in Japan coincided with someone's milestones — starting school, entrance exams, first job — plus hit songs and anime from their school days. These topics are listed in Japanese.
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📜History of any year
Enter a Western or era year to see the historical period, the zodiac year, major events and the ages (kazoe) of historical figures alive then — e.g. in 1582, Oda Nobunaga was 49. Event notes and names are in Japanese.
How to use it (3 steps)
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Choose what to look upSwitch between “Era converter”, “Age” and “Birth year” with the tabs at the top. Each has a one-at-a-time and a bulk mode.
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Enter the numbersFor era conversion, pick an era and year; for age, enter a date of birth; in “Birth year”, enter an age.
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Check the resultThe conversion, age, kazoe age, zodiac and more are shown, ready to copy onto a form.
When it comes in handy
Enjoying Japanese history books and period dramas
Enter an era year or a Western year in the “Era converter” tab and “History of this year” appears below.
Tenshō 10 is 1582, the year of the Honnō-ji Incident. Oda Nobunaga was then 49 by traditional reckoning, Toyotomi Hideyoshi 46 and Tokugawa Ieyasu 41. Check age gaps between historical figures, or how old someone was at a given event. Enter BC years as negative numbers such as -300 to see the period name (e.g. Yayoi period).
Japan used the old lunisolar calendar until Meiji 5 (1872). This tool matches era years to Western years as standard timelines do, so an event late in a lunar year may actually fall in the next Western year. Lunar months and days are not converted to Western dates.
Writing your date of birth on Japanese forms
Convert it in the “Era converter” tab to avoid mistakes.
Forms at city halls, banks and other institutions in Japan often ask for dates in the Japanese era system. Doing the Shōwa / Heisei / Reiwa math in your head easily goes wrong around era changes. This tool shows both eras for a changeover year, and the full-date converter gives the exact one.
Checking age on a specific date
Change the reference date to get the age on any past or future date.
Sometimes you need the age on a date other than today — on a contract date, a start date, or as of next April 1. Just change the reference date and it recalculates.
Under Japanese law (the Act on Calculation of Age), a person's age goes up on the day before their birthday — which is why children born on April 1 join the school year above. By default this tool uses the everyday rule (age goes up on the birthday); tick “Use legal counting” to switch to the legal rule.
Finding small-talk topics with Japanese clients
Use the “Conversation starters” shown after an age calculation.
First, major events in Japan that coincided with the person's life milestones are listed. The same earthquake means something very different to someone who was in elementary school, about to take university entrance exams, or just starting work. Events are shown with the school year they fell in, so you can start a conversation close to the person's own experience.
It also lists songs that were hits in Japan during their teens, anime and games popular in their elementary school years, and companies and shops founded around their birth. Having one topic from their generation helps keep a first visit or phone call going. The topics themselves are in Japanese.
It's meant for a line like “People your age must remember when ◯◯ was popular.” Bringing up someone's age directly can be rude, so use tact.
Calculating ages for a whole list
Choose “Bulk” in the “Age” tab and paste one date of birth per line.
Lists of applicants or members with a mix of Japanese era and Western birth dates can be processed as they are. Set the reference date to a selection or contract date to get everyone's age on the same day. Copy the results for a spreadsheet or save them as CSV. Nothing you enter leaves your browser.
We make no guarantee as to the accuracy or completeness of the explanations on this page or the results of this tool. How age is counted can differ by system and situation (under Japanese law, age goes up the day before the birthday). Events, hit songs, trends, company foundings and historical figures are selected highlights, not a complete list, and are written in Japanese. Pre-Meiji eras, events and birth/death years were checked against standard timelines (public sources such as Wikipedia), but sources may differ. Period boundaries are approximate, and a song's release year may differ from the year it became a hit. Romanized era names before Meiji are generated automatically from their readings. For official procedures, always check official sources. See our Terms of Use and Privacy Policy for details.