Age calculator
Enter a date of birth and get the exact age in years, months and days, the totals in months, weeks, days and hours, the weekday you were born, and a countdown to the next birthday. Fully offline.
Open Age calculator →What is the age calculator?
An age calculator that works out the exact age from a date of birth in years, months and days, plus the totals in months, weeks, days and hours. It also shows the weekday you were born and a countdown to the next birthday. Everything runs in your browser and works fully offline.
How to use Age calculator
- Enter the date of birth — Pick the date of birth from the first date field. The results appear as soon as a valid date is chosen.
- Set the date to measure to — The "Age at the date" field defaults to today. Change it if you want the age on a different past or future date.
- Read the exact age — See the precise age in years, months and days, with the same span shown as totals in months, weeks, days and hours.
- Check the extras — Look below the totals for the weekday you were born on and a countdown to the next birthday.
Frequently asked questions
Can I calculate age on a date other than today?
Yes. The "Age at the date" field starts on today but you can set any date — past or future — to find the age on that day.
Is my date of birth uploaded anywhere?
No. The calculation happens entirely in your browser, so the dates you enter never leave your device, and the tool keeps working offline.
How is the exact age worked out?
It counts whole years, then the remaining whole months, then the leftover days, accounting for months of different lengths — so the years/months/days figure is precise.
What does the next-birthday countdown show?
It shows how many days remain until the next birthday relative to the "age at" date, along with the weekday that birthday falls on. On the day itself it shows a celebration message.
What if the second date is before the date of birth?
The tool won't calculate a negative age — it shows a note asking you to pick an "age at" date that is on or after the date of birth.
Tips
- Leave the second field on today's date for a normal current-age calculation.
- Set a future date to see how old someone will be on a specific occasion.
- Use the weekday line to find out which day of the week a birth date fell on.
- The month and week totals are handy for tracking a baby's age in early months.