Age Calculator
Exact age plus birthday countdown ยท By Stuart Mathieson · Updated October 2026
Defaults to today if left blank
Results
Age
Total Days Lived
Total Weeks
Next Birthday In
How the age calculator works
The calculator counts complete years first, then complete months, then the remaining days. A year or month only counts once you reach the same date again - someone born on 15 May is still 35 on 14 May and turns 36 on 15 May.
Worked example
Born on 15 May 1990, as of 23 October 2026:
- 15 May 1990 to 15 May 2026 is 36 years.
- 15 May 2026 to 15 October 2026 is 5 months.
- 15 October to 23 October is 8 days.
- In total that is 13,310 days, or 1,901 complete weeks, and the next birthday is 204 days away.
Total days count the days that have passed between the two dates, using your device's calendar. The time of day you were born isn't included.
Special cases
- Birthdays on 29 February. In years without a 29 February, this calculator treats 1 March as the birthday, so someone born on 29 February 2004 turns 23 on 1 March 2027. Some countries and organizations use 28 February instead, so check if it matters for an official form.
- Age on another date. Set the "as of" date to find your age on a past or future day - for example, on an application deadline or the day a policy starts.
- Months have different lengths. Because months run from 28 to 31 days, the same number of days can be shown as a different mix of months and days depending on the dates involved.
Frequently asked questions
How is the years/months/days age calculated?
It counts full calendar years, then full calendar months, then remaining days between your date of birth and the "as of" date - the same way you'd count on a calendar, not just by dividing total days.
Can I calculate age as of a date other than today?
Yes - the "Calculate age as of" field defaults to today but can be set to any date, useful for figuring out age at a past or future event.
Does this store my date of birth anywhere?
No - the calculation happens entirely in your browser and nothing is sent to a server. If you calculate and the link becomes shareable, the date is only encoded in that URL, not stored by us.
How do I find out how old I will be on a future date?
Enter your date of birth and set the "as of" date to the future date. The calculator shows your exact age on that day.