Everyday Calculators & Converters
Age Calculator
How old am I, exactly? Years, months and days from a date of birth, plus the next birthday.
- Runs in your browser
Tell us the dates
Your age
Your age pops up here
Enter a date of birth, then hit Calculate age. Copy and Share appear with the result.
You changed something. Hit Calculate to refresh.
Seconds alive right now
How to calculate your age from your date of birth
Enter the date of birth
Use the date picker, or type the date. Add a name if you like.
Check the “as of” date
It starts at today. Change it to see an age on any other day.
Press Calculate age
See the exact age, the next birthday and the totals. Copy or share them. Comparing two birthdays? Try the Age Difference Calculator.
How your age is counted
Dates are read as calendar days, so time zones and clock changes can’t move them.
- Years, months, days
- Subtract the years, months and days separately. If the days come out negative, take one month off and add the days of the month before the “as of” date; if the months come out negative, take one year off and add 12.
- A worked example
- Born 31 January 2000, as of 15 January 2005: days 15 − 31 = −16, so take a month off and add December’s 31 days (15 days). Months 1 − 1 − 1 = −1, so take a year off and add 12 (11 months). Years 2005 − 2000 − 1 = 4. Answer: 4 years, 11 months, 15 days.
- 29 February
- In leap years the birthday is 29 February. In other years it counts on 1 March, or on 28 February if you choose that.
- Totals
- Total days are the calendar days between the two dates; total weeks are whole weeks. Only “Seconds alive right now” uses the clock, and it runs only while “as of” is today.
Questions
How do I calculate my age in years, months and days?
Calendar-exact: whole years first, then whole months, then the days left over. When the day of the month hasn’t come round yet, we borrow the days of the month before the “as of” date, so 31 January to 15 March 2025 is 1 month and 12 days.
What if I was born on 29 February?
In leap years your birthday is 29 February. In other years you choose: 1 March (the default) or 28 February. The choice changes the next-birthday date and the day your age goes up.
Can I see my age on a past or future date?
Yes. Change the “as of” date to any day from 1900 onwards and press Calculate age. Press Today to go back to today’s date.
How many days old am I?
Enter your date of birth and press Calculate age: “Total days” counts every calendar day from your birth date to the “as of” date, leap days included, and “Total weeks” shows the whole weeks. For a running count, watch “Seconds alive right now”.
Is my date of birth stored or sent anywhere?
No. The calculation runs in your browser and nothing is saved or sent. Your dates only go into a link if you press Share link. The name you type is never put in the link or the page address.