Age Calculator
Enter a date of birth to see the exact age today, or on any other date, in years, months and days, with the weekday of birth and the days to the next birthday.
Worked out on your device. The date of birth isn’t sent, saved or put in the page address.
An exact age, on any date
Forms, sign-ups and entry rules often ask for an age on a particular date, and some want it in months or days. Working it out by hand means counting birthdays, then months, then days, with short months and leap years in the way. This calculator does the counting for any date of birth from year 1 to 9999.
How to use it
- Enter the date of birth.
- Leave Age on this date as today, or change it to the date you need, such as a deadline or a cut-off date.
- Read the age in years, months and days, then the same age in months, in weeks and in days.
- Below that are the day of the week of the birth and the date of the next birthday, with the days left until it.
How the age is counted
- Years: one for each birthday reached by the chosen date. On a birthday itself, the new year counts, and the tool says it’s a birthday.
- Months and days: whole months since the last birthday, then the days left over. A month runs to the same day in the next month, or to that month’s last day when it’s shorter.
- Totals: the age in months is whole months since the birth date; weeks and days come from the exact number of days.
- February 29: in other years, you choose February 28 or March 1 as the birthday, and every figure follows your choice.
Worked examples
- Born June 8, 1990: on October 20, 2026 the age is 36 years, 4 months and 12 days, which is 436 months and 12 days, or 13,283 days. June 8, 1990 was a Friday, and the 37th birthday is 231 days later.
- Born February 29, 2000: on February 28, 2026 the age is exactly 26 with the February 28 rule, or 25 years, 11 months and 30 days with the March 1 rule.
Good to know
- Dates only: the tool counts calendar days, leaving out the time of birth and time zones.
- Private: the date of birth stays on your device; nothing is sent or saved.
- Other spans: for the time between any two dates, or the date a number of days, weeks or months away, use the Date Difference Calculator.
- Leaving a job? The Notice Period Calculator works out the last day of a notice period.
Frequently asked questions
How does it handle a February 29 birthday?
In years without a February 29, you choose where the birthday falls: February 28, which is the starting choice, or March 1. The choice appears when you enter February 29, and the age, the next birthday and the countdown all follow it.
How are the months counted?
A month of age runs to the same day in the next month. When that month is shorter, its last day stands in, so someone born on January 31 is 1 month old on February 28. Every figure in the tool uses this rule.
Can I find an age on a past or future date?
Yes. Change Age on this date to any date after the date of birth, such as the first day of a school year or an entry cut-off date, and every figure updates. The Today button puts today’s date back.
Is the date of birth saved or sent anywhere?
No. The age is worked out on this page, on your device. Nothing is sent, saved or put in the page address, and reloading the page clears the date of birth.