Age calculator: how old am I, exactly?
Your age in years, months and days, today or on any date you choose, plus the same span counted in weeks, days, hours and minutes.
How the age calculation works
People state age in completed units: you are 34 until the morning of your 35th birthday, however close it is. So the calculator counts full years first, then full months since your last monthly anniversary, then leftover days.
The awkward case is a birthday on the 29th, 30th or 31st. There's no 31 February, so we use the last day of shorter months as the monthly anniversary. Someone born on 31 January is "one month older" on 28 February (29 in a leap year). Spreadsheet formulas such as Excel's DATEDIF handle this differently and can show a negative or skipped day, which is why online calculators sometimes disagree by one day.
Leap-day babies (29 February) legally come of age on 28 February in some places (such as New Zealand and Taiwan) and on 1 March in others (such as England and Wales). Here, 28 February is treated as the birthday in common years.
Age in different cultures
Traditional East Asian age reckoning counts a newborn as one year old and adds a year at Lunar New Year, so it can be up to two years higher than international age. South Korea officially switched to international age for legal purposes in June 2023. This calculator uses international age.
More from your birth date
Questions people ask
How do I calculate my exact age?
Subtract your birth year from the current year, then subtract one if your birthday hasn't happened yet this year. For months and days, count whole months since your last birthday, then the days since your last monthly anniversary. The calculator does this automatically, including leap years.
How old will I be on a future date?
Change the "Age on this date" field to any future date and the calculator shows the exact age you will be then, in years, months and days.
How many days old am I?
The calculator shows your age in total days. For milestones such as your 10,000th day, use the days lived page.
Why do some age calculators give a different number of days?
They handle birthdays on the 29th to 31st differently. Months have different lengths, so "one month after 31 January" can be defined as 28 February or 3 March. BirthdayBump uses the last day of the month, which matches how most people count.