Age Calculator

Age Calculator works out an exact age from a date of birth, in years, months and days, and shows the total days lived and the date of the next birthday. It suits anyone filling in a form, planning a birthday, or checking how old someone will be on a given day. The second date is today by default, and you can change it to see an age in the past or the future.

How to use

1. Pick the Date of birth with the date field, or type it in your browser’s date format.
2. Leave Age on as it is to measure the age today, using the calendar of your device, or pick another date to measure on.
3. Read the four cells: Years, Months, Days and Total days. The first three add up to the exact age, and the last counts every day between the two dates.
4. Under them, a sentence names the next birthday with its weekday, how many days away it is, and the age being reached.
5. If a date is missing, or the birth date comes after the age-on date, a message says so.

Examples

Born on 15 May 1990 and measured on 2 October 2026, the age is 36 years, 4 months and 17 days, which is 13,289 days in all. The next birthday is Saturday, 15 May 2027, 225 days later, turning 37.

For a birth on 29 February 2000, measured on 28 February 2001, the age is exactly 1 year. In a year that is not a leap year, the birthday is counted on 28 February, and the next birthday after 2 October 2026 is Sunday, 28 February 2027.

Limits

It uses the Gregorian calendar for every date, even before that calendar was adopted, and accepts years from 1 to 9999. The age is calendar based: when the birth day does not exist in a month, the last day of that month is used, so a 29 February birthday falls on 28 February in a common year. Some legal systems count it on 1 March instead. The time of birth and time zones are not used.

FAQ

How is the age counted when I was born on 29 February?

In a year that is not a leap year, the birthday is treated as 28 February, and in a leap year it is 29 February. Some countries use 1 March for legal purposes, so check the rule that applies to you.

What does the age-on date do?

It sets the day the age is measured on. Leave it as today for a current age, or choose a future date to see how old someone will be then, or a past date for an age at that time.

Why does it refuse a birth date in the future?

An age cannot be negative, so a birth date after the age-on date has no result. The message shows both dates. Change either one, and the age appears at once.

Is my date of birth sent anywhere?

No. Both dates stay in this page on your device, and the calculation runs there without any upload.