Age Calculator
Enter a date of birth to get an exact age in years, months and days, on today's date or any other. You also see the total time lived and the countdown to the next birthday.
- Runs in your browser
- No sign-up
- Free to use
Enter a date of birth
The exact age appears here as soon as you pick a date.
Next birthday
How to use Age Calculator
- Select or type the date of birth.
- Leave “Age on” set to today, or pick another date to find the age on that day.
- Read the exact age, shown as years, months and days.
- Check the extra figures: total months, weeks, days and hours, the weekday of birth and the next birthday.
Age Calculator features
Exact calendar age
Counts whole years, then whole months, then remaining days, accounting for month lengths and leap years.
Age on any date
Find out how old someone was, or will be, on a particular day.
Totals in other units
The same span expressed as months, weeks, days, hours and minutes.
Next birthday countdown
Days remaining, the weekday it falls on and the age that will be reached.
Leap-day birthdays handled
For people born on 29 February, the birthday in common years is taken as 1 March.
Instant and private
Dates are processed in your browser and are not stored.
When to use Age Calculator
- Filling in forms that ask for age in years and months on a specific date.
- Checking eligibility against an age limit for school admission, exams, jobs or sports.
- Working out a child's exact age for medical or developmental records.
- Finding how many days old you are, or how long until a milestone birthday.
Age Calculator FAQ
How is exact age calculated?
Full years are counted from the date of birth to the most recent birthday, then full months from that birthday, and the remaining days after that. This is the method used on official forms and differs slightly from dividing the number of days by 365.
How are leap years handled?
The calculation uses real calendar dates, so 29 February is included in the day totals wherever it occurs. Someone born on 29 February is treated as having their birthday on 1 March in years that are not leap years.
Why might my age differ by one day from another calculator?
Calculators differ on whether to count the end date and on which time zone defines “today”. This tool uses your device's local date and does not count the end day as a full day lived.
Can I calculate age on a past or future date?
Yes. Change the “Age on” date. Choosing a date before the date of birth shows a message instead of a negative age.
Is the date of birth saved anywhere?
No. It stays in your browser and is discarded when you leave the page.
Counting age correctly
Age seems simple until you need it exactly. Months have 28 to 31 days, so “three months and five days” depends on which months are involved. The convention used for legal and administrative purposes is to step through the calendar: add whole years to the birth date until the next one would pass the target date, then whole months, and count the days left over.
Different cultures also count age differently. The international system used here starts at zero at birth and increases on each birthday. Some East Asian traditions count a baby as one year old at birth and add a year at the new year, which can make a person one or two years “older” by that reckoning.
Exact age calculations come up more often than you might expect. School admissions and youth sports leagues set cut-off dates, so a child's age on a specific day decides the class or team. Pension, retirement and insurance rules often depend on the age reached by a given date, visa and driving-licence applications have minimum ages, and medical dosing for children is sometimes based on age in months. In each case, the age on the relevant date is what counts, not the age today, which is why it helps to calculate it for a chosen date.