Toolstia / Age and date difference calculator
Calculate age or the time between two dates
Enter a date of birth, or any start date, and see the exact difference to today or to another date, in years, months and days, plus total days and weeks. It also counts down to the next birthday.
Dates are compared as calendar dates, so time zones and clock times do not affect the result.
How it works
- Choose the start date, for example a date of birth.
- Leave the end date as today, or choose another.
- Read the result and the extra counts below it.
How the difference is worked out
The tool counts complete years, then complete months, then the days left over, using the real length of each month. Total days are counted exactly on the calendar.
Birthdays on 29 February
In years that are not leap years, a 29 February birthday is counted on 28 February for the countdown. Legal systems differ on which day applies, so check local rules if it matters.
Other uses
Any two dates work: the length of a project, time since an event, or days until a deadline if the end date is in the future.
Time zones
Only calendar dates are used, so the result does not change with your time zone or the time of day.
Questions
Is my date of birth stored?
No. It is used only in your browser to work out the answer and is never sent or saved.
Can the end date be in the future?
Yes. You can count how long until an event. The start date just has to be earlier than the end date.
Why does it fill in today's date after the page loads?
The page is built in advance, so today's date is added by your browser when it opens.