Find an exact age in years, months and days on any date, with the total in months, weeks and days and a countdown to the next birthday.
How to use the age calculator
- Enter the date of birth.
- Leave “Age on this date” as today, or change it to find an age on a past or future date.
- The age, totals and next birthday update straight away.
How the age is worked out
The calculator counts whole years first, then whole months since the last birthday, then the days left over. This is how ages are usually stated, and it is different from dividing a number of days by 365.
Months have different lengths, so a month step keeps the same day number and moves back to the last day of the month when that day does not exist. One month after 31 January is 28 February, or 29 February in a leap year.
Someone born on 31 January 2026 is, on 1 March 2026, 1 month and 1 day old: the one-month point is 28 February, and 1 March is one day later. That is 29 days in total.
Age in months, weeks and days
Below the age, the calculator shows the same span as single totals. Total months is the number of full months since birth. Total weeks shows whole weeks only, so 13,319 days is 1,902 weeks with 5 days left over.
These totals are useful for babies and young children, whose ages are often given in weeks or months, and for counting the days to or from an important date.
Formula
Years = full birthdays passed
Months = full months since the last birthday
Days = days since the last full month
Total days = days between the two dates
Total days counts from the date of birth to the chosen date, not counting the birth date itself.
Worked examples
Someone born on 15 May 1990 is, on 1 November 2026, 36 years, 5 months and 17 days old. That is 437 months, 1,902 whole weeks or 13,319 days. Their next birthday is 15 May 2027, 195 days later.
Someone born on 29 February 2000 is, on 28 February 2027, 26 years, 11 months and 27 days old. In 2027 there is no 29 February, so the calculator counts the birthday on 1 March, when they turn 27.
When an exact age is useful
- Checking an age limit or cut-off date for school entry, a licence, a competition or an insurance quote.
- Working out an age on a past date, such as the date of an event or document.
- Counting down to a birthday or anniversary.
- Finding how long ago anything started, such as a company, a building or a pet’s adoption.
Official forms may follow their own rule for leap-day birthdays or cut-off dates. Where it matters, check the rule that applies.
Frequently asked questions
How are 29 February birthdays handled?
In years without 29 February, this calculator counts the birthday on 1 March. Rules differ between countries, and some use 28 February instead, so check the one that applies to you.
Does my time zone change the result?
No. The calculation uses calendar dates only, so it gives the same answer anywhere.
Can I calculate an age in the past or future?
Yes. Change “Age on this date” to any date after the date of birth.
How many days old am I?
See the Total days row. It counts every day from your date of birth to the chosen date, not counting the birth date itself.
Why not just divide the days by 365?
Leap years add an extra day roughly every four years, so dividing by 365 slowly drifts. Counting real birthdays gives the age people and forms expect.