About the Age Calculator
Need an exact age for a form, an application or just out of curiosity? This age calculator gives the age in years, months and days, correctly handling months of different lengths and leap years.
You can also choose a different date to find how old someone was, or will be, on that day.
How to use it
- Choose the date of birth.
- Optionally choose another date; leave it empty to use today.
- Press Calculate.
- See the exact age, total days and days until the next birthday.
Formula
Years, months and days are counted forward from the birth date, borrowing days from the previous month when needed.
Example
Someone born on 15 March 2000 is 26 years, 6 months and 4 days old on 19 September 2026.
Common mistakes to avoid
A quick way to find age is to subtract the birth year from the current year. This can be off by one if the birthday has not yet happened this year. The calculator compares the full dates, so you get the exact age in years, months and days.
Be careful with dates near midnight and time zones. The calculation uses the dates you enter, and the age shown uses today's date unless you change it.
Practical examples
A child born on 1 January 2020 will be 6 years old on 1 January 2026, but only 5 years old on 31 December 2025. Reading the exact date rather than only the year helps with school admission rules and sports age groups, which often use a cut-off date.
Age can also help you plan events. If a business opened on 10 March 2001 and you want to mark its 25th anniversary, enter that date to see the exact number of years, months and days. For legal purposes, always use the official document that records the date of birth, because a calculator is not an official record.
Where exact age matters
Exact age is often needed for school admission cut-off dates, government job and exam eligibility, retirement planning, insurance forms and passport applications. Many forms ask for age "as on" a specific date, which is what the optional second date is for.
Frequently asked questions
How are 29 February birthdays handled?
In years without 29 February, the next birthday is counted as 28 February.
Is my date of birth stored?
No. The calculation runs in your browser and nothing is saved or sent.
Can I calculate the age of something other than a person?
Yes. Enter any start date, such as the day a business opened.
Why might another calculator differ by a day?
Some tools count the end date differently. This one counts complete days between the two dates.