Skip to content
K-ALL

Age calculator

Enter a date of birth to get the exact age today in years, months and days, how many days and weeks that is, and how long until the next birthday. Change the second date to see an age on any other day.

Gregorian calendar arithmetic, with worked examples checked by hand. Checked October 29, 2026 (sources). Free, no sign-up, nothing you type is stored.

Date of birth
Age on
Your date of birth stays in your browser. It only goes into the link if you share it.

Age

-

Loading today’s date…

Enter a date of birth to see the exact age.

Age is counted in completed years: you turn one year older on your birthday. The day of birth is day 0 in the day count.

How the age is worked out

The calculator compares the two dates on the calendar. It counts the birthdays that have passed (the age in years), then the whole months since the last birthday, then the days left. Time of birth and time zone are not used.

ExampleBorn Sunday, July 15, 1990, age on Thursday, October 29, 2026

Years, months, days
36 years, 3 months, 14 days
Total months
435
Total days
13,255
Next birthday
Thursday, July 15, 2027 (in 259 days)
Age
36 years

February 29 birthdays

Born Tuesday, February 29, 2000
DateAgeWhy
Feb 28, 202726 yearsFebruary 28 has not ended yet
Mar 1, 202727 yearsfirst day after the missing Feb 29
Feb 29, 202828 yearsleap year: the birthday itself

Some places and services treat February 28 as the birthday in common years. Only that one day can differ.

FAQ

In completed years: the number of birthdays you have had. You become one year older on your birthday, not before.

For someone born Sunday, July 15, 1990, on Thursday, October 29, 2026 that is 36 years (36 years, 3 months, 14 days).

Count the days from your date of birth to today. Someone born Sunday, July 15, 1990 is 13,255 days old on Thursday, October 29, 2026.

The day you were born is day 0, so a baby is 1 day old the next day.

In leap years, on February 29. In other years this calculator counts the new age from March 1, the first day after February 28 has ended.

Feb 28, 2027
26 years
Mar 1, 2027
27 years
Feb 29, 2028
28 years

Practice differs: some laws and services use February 28 instead. The result can only differ on that one day, so check with the organisation involved if it matters (a licence, a contract).

Yes. Change “Age on this date” to any date, for example to see how old someone was on a given day or will be at a deadline.

Years alone hide up to 11 months. The breakdown counts whole calendar months after the last birthday, then the days left over.

The day before the birthday in the example above, the age is 35 years, 11 months, 29 days.

No. This is international age, which South Korea has also used for legal purposes since June 28, 2023. The traditional Korean “counting age” adds one or two years and is on our Korean age calculator.

No. The calculation runs in your browser and nothing you type is sent to our server. It only goes into the link if you press a share button.

Sources

Spotted a mistake? Tell us. No ads on this page.