Age Calculator

This age calculator works out exact age in years, months and days from a date of birth, as of today or any other date. It also gives the total months, weeks and days lived, the day of the week you were born and how long it is until your next birthday.

Result

Age: 36 years, 4 months, 13 days

Next birthday	Tuesday, June 15, 2027 (in 230 days)
Total months	436
Total weeks	1,897
Total days	13,284
Born on a	Friday

Results update as you type.

How Age Is Calculated

Exact age is counted the same way people count birthdays:

Years: the number of birthdays that have passed.
Months: the number of full months since the last birthday.
Days: the days left over since the last full month.

Total days lived is simply the number of days between the two dates, which includes every leap day.

Worked Example

Born June 15, 1990, age on October 28, 2026:

The most recent birthday was June 15, 2026, which is the 36th.
From June 15 to October 15 is 4 full months.
From October 15 to October 28 is 13 days.

Age: 36 years, 4 months, 13 days. That’s 436 months, 1,897 full weeks, or 13,284 days. The next birthday, June 15, 2027, is 230 days away.

Tips

Ages on forms

Most forms ask only for whole years: the number of birthdays you’ve had. The years figure in the result is that number.

Age in months for babies

Pediatricians often track a baby’s age in months, and in weeks for newborns. The totals in the result give both.

Days between any two dates

To count the days between two dates that aren’t birthdays, such as a project start and end, use the date difference calculator.

Planning ahead

For a pregnancy, the due date calculator counts forward from the first day of the last period.

Frequently Asked Questions

How do you calculate your exact age?

Count the full years since your birth date, then the full months since your last birthday, then the days since the last full month. Someone born on June 15, 1990 is 36 years, 4 months and 13 days old on October 28, 2026, because their 36th birthday was June 15, 2026, four full months take them to October 15, and 13 more days reach October 28.

How old am I in days?

Count the days between your date of birth and today. The calculator does this exactly, including every leap day. Someone born on June 15, 1990 had lived 13,284 days by October 28, 2026.

How is age counted for someone born on February 29?

In years without a February 29, this calculator treats February 28 as the birthday, so a person born on February 29, 2000 turns 27 on February 28, 2027. Some laws and organizations use March 1 instead, so check if it matters for a legal purpose.

Can I calculate age on a past or future date?

Yes. Change the "Age on" date to any date after the birth date, for example to find how old someone was on their wedding day, or how old they will be on a future date.

What day of the week was I born?

The calculator shows it below your age. June 15, 1990, for example, was a Friday.

Why might a different calculator give a slightly different age?

Calculators can differ on how they count leftover days at month ends, such as from January 31 to March 1. This one steps forward a whole month at a time, so January 31 plus one month is February 28 (or 29), and January 31 to March 1 is 1 month and 1 day. Total days lived is always the same.

Sources & Assumptions

Ages use the Gregorian calendar, with leap years every 4 years except century years not divisible by 400 (so 2000 was a leap year and 1900 was not).
National Institute of Standards and Technology (NIST) — Time and Frequency from A to Z, "Leap year" (Gregorian rule: century years are leap years only if divisible by 400)
Month ends clamp when stepping forward by months, so February 29 birthdays fall on February 28 in common years. "Today" is your device's date.

Last reviewed: October 28, 2026