How to use the age calculator
- Pick your date of birth in the first field. Your phone or browser shows a date picker.
- The second field starts on today's date. Change it to find your age on any other day, past or future; click Today to return.
- Read your age in years, plus the exact breakdown in years, months and days, total months, weeks and days, and the weekday you were born.
- Below the result you see how many days are left until your next birthday and which weekday it falls on.
How exact age is calculated
Counting age is harder than subtracting years, because months have 28 to 31 days and leap years add February 29. The calculator works the way people count in everyday life:
- It counts how many whole months have passed since your birth date. A month is complete when the same day number is reached again; if that day does not exist (for example the 31st in a 30-day month), the last day of the month is used.
- Whole months are split into years and months (12 months = 1 year).
- The days left over after the last complete month are counted on the calendar.
Totals in days and weeks come from the exact number of calendar days between the two dates. All of this uses dates only, without clock times, so time zones and daylight saving time cannot shift the result by a day.
Worked example
Someone born on May 15, 1990 asks their age on October 21, 2026. From May 15, 1990 to May 15, 2026 is 36 years. From May 15 to October 15 is 5 more months, and from October 15 to October 21 is 6 days. Their age is 36 years, 5 months and 6 days.
That is 13,308 days in total, or 1,901 weeks and 1 day. They were born on a Tuesday, and their next birthday, May 15, 2027, is a Saturday, 206 days away, when they turn 37.
Special cases
- Born on February 29: in common years the birthday is counted on February 28, so you still age by one year every year. Some countries use March 1 for legal purposes; check local rules for official documents.
- End-of-month births: someone born on January 31 is one month old on the last day of February (28 or 29), because February has no 31st.
- Age in other cultures: traditional East Asian age reckoning counts a baby as one year old at birth. This calculator uses the international system, where age starts at zero.
Practical uses
- School and sports cut-off dates: set the second field to the cut-off date to see whether a child qualifies.
- Retirement and benefits: check your exact age on the date a pension or benefit starts.
- Forms and visas: many applications ask for age on the date of travel or on a specific deadline rather than today.
- Milestones: find out when you reach 10,000 days (about 27 years and 4 months) or 1,000 weeks (about 19 years and 2 months).
Your date of birth never leaves your device: the calculation runs entirely in your browser.
Frequently asked questions
How is exact age calculated?
The calculator counts whole years and months from your date of birth, then the remaining days. It works with calendar months, so it handles months of different lengths and leap years correctly.
What if I was born on February 29?
In common years your birthday is counted on February 28, the last day of February. In leap years it falls on February 29 as usual.
Can I calculate age on a past or future date?
Yes. Change the 'Age on this date' field to any date, for example to check your age on a school cut-off date or a retirement date. Click Today to go back.
Is my date of birth stored?
No. The calculation runs in your browser and nothing is sent or saved.