Exact age in years, months and days, and next birthday.
Enter a date of birth in the age calculator and you get the exact age in years, months and days. It also shows your age as total months, weeks, days and hours, and counts down the days to your next birthday. You can work out age on any date, not just today, which is handy for forms, school entry cut-offs, insurance and pension dates.
Using the Age Calculator
- Pick the date of birth.
- Age on this date is set to today. Change it to find someone’s age on a past or future date.
- Read the exact age in years, months and days, followed by:
- total months, weeks and days, and total hours,
- the day of the week they were born on, and
- how many days are left until the next birthday.
How Age Is Calculated
The calculator counts complete years first, then complete months, then the remaining days. When the day of the month in the second date is earlier than the birth day, it borrows the days of the previous month, the same way you would on paper. This is how age is normally worked out for official purposes in the US and UK.
Worked Examples
Born 15 June 1990, age on 1 January 2026.
- Exact age: 35 years, 6 months and 17 days.
- Total: 426 months, 1,854 weeks and 6 days, or 12,984 days (311,616 hours).
- Born on a Friday.
- Next birthday: 15 June 2026, which is 165 days away.
Checking an age limit. A school requires children to be 5 by 1 September 2026. A child born on 2 September 2021 is 4 years, 11 months and 30 days on that date, so they miss the cut-off by one day.
When Exact Age Matters
- School entry. Many schools set a cut-off date, so a child must reach a certain age by a set day.
- Retirement and pensions. State pension age and many workplace pensions depend on an exact birth date.
- Insurance and loans. Premiums and eligibility often change at a particular birthday.
- Sports and competitions. Age groups are usually set by age on a fixed date, such as 1 January or 31 December of the season.
- Visa and ID forms. Some forms ask for age on the date of application, not on today’s date.
In each case, set “Age on this date” to the cut-off date, not today.
Leap Year Birthdays
People born on 29 February only have a calendar birthday every four years. In other years, this calculator treats 1 March as the day they turn a year older, which is the rule commonly applied in the UK. Some countries and organisations use 28 February instead, so check the rule that applies to you if a date is important.
Why Ages Can Differ Between Calculators
- Leap year rules for 29 February birthdays, as above.
- Month lengths. “One month” from 31 January has no matching day in February, so different tools handle it differently.
- Time zones. Someone born late in the evening in one time zone was born on the next day in another. This calculator works with calendar dates only, not times.
Other Date Tools
- To find the weekday for any other date in history, use the day of the week calculator.
- To add or subtract days, weeks or months from a date, use the date calculator.
Age Calculator FAQs
How old am I in days?
Enter your date of birth and leave the second date as today. The total days figure is your age in days. It counts every leap day you have lived through.
Can I calculate age at a date in the future?
Yes. Change “Age on this date” to any future date to see how old someone will be then, for example on a retirement or graduation date.
Does the calculator count the day of birth?
It counts the time between the two dates, so on your birthday you are an exact number of years old, with 0 months and 0 days.
Do you store the dates I enter?
No. The calculation happens in your browser, and the dates are not sent to us.
How we checked this page: the examples were counted by hand and match the calculator, including the total days and the leap-year birthday rule.