Age Calculator
Calculate full age from your date of birth in your browser, plus Japanese era names, a simple year-based zodiac animal, a star sign from month and day, child-style month counts under six, day-count milestones, days until a chosen adulthood age (18 or 20), and a multi-person table with copyable text. Nothing is sent to a server.
Tool
Enter your date of birth and a reference date to see results.
Multiple people
Only rows with a date of birth are calculated.
Names are optional—you can leave them blank.
| Name | Date of birth | Age | Details | Next birthday |
|---|
Overview
- Enter a date of birth and reference date to see full age, a year/month/day breakdown, days since birth, and days until the next birthday.
- See key dates with Japanese era labels where supported, plus zodiac animal and star sign.
- Review day-count milestones, month-based details for children under six, and days until age 18 or 20 on the same results screen.
- Use the Multiple people tab to compare up to 20 people against one shared reference date.
- Age is calculated in full years. Change the reference date to see age on a specific calendar day.
- Dates are handled as local calendar dates without time-of-day shifts.
- If you were born on February 29, February 28 is used as your birthday in non-leap years.
- Weeks use floor division by 7; the calendar year-month-day span since birth is shown for clarity.
- The zodiac animal uses the Gregorian year only, not a strict lunar-calendar rule set. The star sign uses popular month-day ranges.
- Legal definitions of adulthood vary by country and context. Adulthood countdowns are practical estimates, not legal advice.
- Dates, names, and reference values are processed only in your browser and are not sent to a server. Names are optional.
When this helps
- Check today’s age
- Forms and applications
- Age on a past or future date
- Days until the next birthday
- Japanese era alongside Western dates
- Child month counts and milestones
- Days until age 18 or 20
- Compare several people on the same date
FAQ
- 1Can I calculate full age as of today or another date?
- Yes. The reference date defaults to today, and changing it calculates full age as of that calendar date.
- 2What if I was born on February 29?
- In non-leap years, February 28 is treated as your birthday.
- 3Is my date of birth saved?
- No. Inputs are processed only in your browser and are not sent to a server.
- 4Can I see Japanese era, zodiac, and star sign?
- Yes. Dates can be shown with Japanese era labels where supported. The zodiac uses the Gregorian birth year, and the star sign uses common month-day ranges.
- 5Can I see month age or milestones?
- Yes. For ages under six, month-based details are shown. The tool also shows the next day-count milestone based on days since birth.
- 6Can I see days until adulthood?
- Yes. Choose 18 or 20 and see the target date and remaining days.
- 7Can I calculate ages for several people?
- Yes. Enter optional names and birth dates and compare everyone at the same reference date.
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