Percentage calculator
Work out percentages and changes.
Age calculator
Find an exact age in years, months and days, with the next birthday countdown.
Choose a date of birth to see the age.
How it works
- 1Choose the date of birth.
- 2Leave the second date empty for today, or pick another date to find the age on that day.
- 3Read the age and the totals.
- 4Check the weekday and the days to the next birthday.
What the options do
- Age on this date
- Measures to any date, for example the age someone was on a certain day or will be on a future one. Empty means today.
Privacy
The numbers you enter are used in your browser only and are never sent to a server. A date of birth is personal data, and this one stays on your device.
Questions people ask
How is the age worked out?
It counts whole years from the birth date, then whole months, then the remaining days. The days borrow from the length of the previous month, as people do by hand.
What if I was born on 29 February?
In non-leap years, the tool counts the birthday as passed on 1 March, since 29 February does not exist that year. Legal rules differ by country.
Which time zone does it use?
Dates are compared as calendar days, with no time of day or time zone, so the result is the same wherever you are.
Can I use it for a child's age in months?
Yes. Total months is shown in the list, and the headline gives years and months.
Is it the same as the age on official documents?
In most countries, yes, since age counts completed years. Some East Asian traditions count differently, so check local rules for forms.