"Before birthday" is your age if this year's birthday hasn't happened yet; "on/after birthday" is your age once it has.
| Birth year |
Era (wareki) |
Zodiac |
Before birthday |
On/after birthday |
How does an age chart (nenrei hayamihyou) work?
An age chart lists, for every birth year, the age a person turns this year, their Japanese era (wareki) birth year, and their zodiac animal — a quick lookup instead of doing the subtraction yourself. Because a birthday may or may not have happened yet this year, most charts show two ages: one for before the birthday and one for on/after it.
This table is generated from today's date in your browser, covering birth years from this year back 120 years, so it always reflects the current year rather than a fixed snapshot.
How do I find my age from my birth year?
Subtract your birth year from the current year to get the age you turn this year (your age after this year's birthday); subtract one more for your age before this year's birthday. Example: born in 2000, in 2026 you turn 26 (2026 - 2000) after your birthday, or you are still 25 before it.
How this age chart is built
- Take today's date from your device and read the current calendar year.
- List every birth year from the current year down to 120 years earlier, one row per year.
- For each birth year, compute two ages: current year minus birth year (on/after this year's birthday), and one less than that (before this year's birthday).
- Look up the Japanese era (wareki) name and year for January 1 of that birth year; for the four transition years (1912, 1926, 1989, 2019) show both applicable eras.
- Compute the 12-animal zodiac sign from the birth year using its remainder when divided by 12.
Age and zodiac formulas
age (after birthday) = current year - birth year | age (before birthday) = current year - birth year - 1 | zodiac index = birth year mod 12
- "After birthday" age assumes this year's birthday has already passed
- "Before birthday" age assumes this year's birthday has not happened yet
- Zodiac cycles every 12 years: remainder 4 = Rat, 5 = Ox, 6 = Tiger, 7 = Rabbit, 8 = Dragon, 9 = Snake, 10 = Horse, 11 = Goat, 0 = Monkey, 1 = Rooster, 2 = Dog, 3 = Pig
Example rows (as of 2026)
| Birth year | Era (wareki) | Zodiac | Before birthday | On/after birthday |
|---|
| 1970 | Showa 45 (昭和45年) | Dog (戌) | 55 | 56 |
| 1989 | Showa 64 / Heisei 1 (昭和64年/平成元年) | Snake (巳) | 36 | 37 |
| 2000 | Heisei 12 (平成12年) | Dragon (辰) | 25 | 26 |
| 2020 | Reiwa 2 (令和2年) | Rat (子) | 5 | 6 |
Frequently asked questions
Why does this chart show two ages instead of one?
Your age changes on your birthday, and a birth year alone doesn't say whether this year's birthday has happened yet. Showing both the "before" and "on/after" age covers both cases without needing your exact birth date.
What does it mean when a birth year shows two era names?
Four birth years in this range (1912, 1926, 1989, 2019) contain an actual era change partway through the year, so someone born in the first part of that year has a different wareki year than someone born after the transition date.
How is the zodiac animal determined from a birth year?
The 12-animal cycle repeats every 12 years in a fixed order (Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, Pig). Taking the birth year modulo 12 gives a consistent position in that cycle, matching the traditional assignment.
Does this table use 満年齢 (kazoedoshi) or the East Asian counting age?
This table uses 満年齢 (man-nenrei), the standard international "full age" that increases by one on each birthday — the age used on official Japanese documents today, not the older East Asian counting-age system that adds a year at New Year's.
Ages are calculated from the current date in your browser and the calendar year only, not the exact birth date, so the "before/after birthday" columns are estimates until you know the specific day; the table covers 121 birth years (this year back 120 years).