How to calculate your age
Your age is the number of full years, full months and leftover days between your date of birth and today. To work it out by hand:
- Full years. Subtract your birth year from this year. If your birthday hasn't come yet this year, take away one.
- Full months. Count the whole months since your last birthday.
- Days. Count the days since the last time the calendar showed your birth day number.
Example: born May 14, 1990, on November 6, 2026.
- Years: 2026 − 1990 = 36. May 14 has already passed, so 36 full years.
- Months: May 14 to October 14 is 5 full months.
- Days: October 14 to November 6 is 23 days.
Result: 36 years, 5 months and 23 days. That's also 437 months, or 13,325 days.
Age on a specific date
Forms and exam notices often ask for your age on a given date, or your age “as on” a cut-off date. Pick Other date next to “Age on” and enter any date, past or future. The calculator counts from your date of birth to that day instead of today.
For example, someone born on May 14, 1990 was 9 years, 7 months and 18 days old on January 1, 2000, and will be 39 years, 7 months and 18 days old on January 1, 2030.
Applying for a government exam in India? The govt exam age calculator works with the cut-off dates and age limits from the notification.
Your age in months, weeks and days
Under the main result you'll find your age in total months and total days; open More details for weeks, hours, a decimal age and a live count of seconds. Born May 14, 1990? On November 6, 2026 that's 437 months, 1,903 weeks or 13,325 days.
For day-count milestones like 10,000 days, use the age in days calculator; to see your life as a grid of weeks, try the age in weeks calculator. Know someone's age but not their birth year? The birth year calculator works it out.
Leap-year birthdays and end-of-month dates
Born on February 29? Non-leap years have no February 29, so the calculator asks whether to count your birthday on February 28 or March 1. Laws and customs differ by country, and the choice only changes the result around your birthday.
Born on the 29th, 30th or 31st? In shorter months, your monthly anniversary falls on the last day of the month. From January 31 to February 28 counts as one full month in a non-leap year.
The calculator uses the date on your device. A time of birth, under More details, only changes the hours and seconds. The how we calculate age page lists every rule with test cases.
Age in years;months for tests
Psychologists, speech-language pathologists and teachers often write a child's age as years;months: 7;3 means 7 years and 3 months. For anyone under 18, the result above shows this format too.
Test manuals differ on the leftover days. Some round them, some drop them, and many worksheets subtract using 30-day months. The chronological age calculator lets you pick the method your test uses and can process a whole class at once.