Age Calculator

How to calculate your age

Enter the date of birth.
Leave “Age on” as today, or change it to any date, such as an exam's cut-off date.
Read the exact age in years, months and days, and the same age in total months, weeks and days.
See how many days are left to the next birthday and which day of the week it falls on.

How the age is worked out

The calculator counts the way you would on a calendar: first the whole years since the date of birth, then the whole months after the last birthday, then the days left over. A month runs from a date to the same date in the next month. When that date doesn't exist, as with 31 January to February, the month ends on the last day of the shorter month.

total days = age-on date − date of birth, and weeks = total days ÷ 7 with the remainder shown as days. Someone born on 29 February has their birthday on 28 February in years without a 29 February.

Worked example

Born on 15 May 1990, on 7 October 2026:

15 May 1990 to 15 May 2026 is 36 whole years.
15 May 2026 to 15 September 2026 is 4 more whole months.
15 September to 7 October is 22 days.
So the age is 36 years, 4 months and 22 days: 436 months, 1,899 weeks and 1 day, or 13,294 days in total.
The next birthday, on Saturday 15 May 2027, is 220 days away.

Days in each month

Days	Months
31	January, March, May, July, August, October, December
30	April, June, September, November
28 or 29	February: 29 in leap years

A leap year is divisible by 4, except century years, which must be divisible by 400: 2000 and 2024 were leap years, 1900 wasn't. For converting dates to and from Unix time, see theUnix timestamp converter.

Common uses

Checking an exam age limit. Government exams and job forms often set an age limit as on a cut-off date. Enter that date to see your exact age on it.
Counting down to a birthday. See how many days are left until the next birthday, which day of the week it falls on, and the age being turned.
A baby's age in weeks or months. Get a baby's age in weeks or months and days, the way doctors and vaccination schedules count it.

Questions

How is the exact age calculated?

By counting completed calendar years, then completed months, then the days left over, the same way you'd count on a calendar. Someone born on 15 May 1990 is 36 years, 4 months and 22 days old on 7 October 2026.

How is age counted for someone born on 29 February?

In years without a 29 February, this calculator treats 28 February as the birthday, so a leap-day baby turns a year older on 28 February. Some countries' laws use 1 March instead, so check the rule if it matters for a legal date.

Can I find my age on a past or future date?

Yes. Change the “age on” date to any day. That's how you check an age limit on an exam or job form that says “age as on 1 August”, for example.

How are months counted when they have different lengths?

A month is counted from a date to the same date next month. When that date doesn't exist, as with 31 January to February, the last day of the shorter month counts as the anniversary.