How do I calculate my age from my date of birth?
- 1Enter the date of birth.
- 2Leave "age on this date" as today, or pick another date — for example the closing date of a job or school application.
- 3Read the exact age in years, months and days, and the totals in months, weeks, days and hours.
- 4See when the next birthday is, how many days are left and the age you will turn.
How is age worked out?
- 01Age = whole years + whole months + days from the date of birth to the chosen date
- 02Total days = calendar days between the two dates (leap days included)
- 03Total weeks = total days ÷ 7; hours ≈ total days × 24
The calculator counts forward from the date of birth: first the whole years, then the whole months, then the days left over. That is the way ages are written on forms and in law — someone born on 15 May 1990 is 36 years, 4 months and 17 days old on 2 October 2026.
When a month is shorter than the birth day (for example born on the 31st), the month counts as complete on that month's last day. Totals in days count every real calendar day between the two dates, so leap years (29 February) are included automatically. Hours and minutes are whole days × 24 and × 1,440 — they ignore the time of birth and clock changes, so they are approximate.
The next birthday is the next time the birth day and month come round on or after the chosen date. For people born on 29 February, the birthday is counted on 28 February in years without a leap day.
Good to know
- For a form that asks for your age "as on" a certain date, set that date in the second box.
- To check a baby's or child's age in months, read the "In months" line.
- Born near midnight or in another time zone? Your age in days can differ by one depending on where you count from.
- You can find the day of the week for any past date by entering it as the date of birth.
Age calculator — common questions
How do I calculate my exact age?
Count the whole years from your date of birth, then the whole months, then the remaining days up to today. This calculator does it for you — enter your date of birth and it shows your age in years, months and days.
How old am I in days?
Enter your date of birth and read the "In days" line. It counts every calendar day since you were born, including leap days.
How is age calculated for someone born on 29 February?
In leap years the birthday is on 29 February. In other years this calculator counts it on 28 February; some countries use 1 March for legal age, so check local rules if it matters.
Can I calculate age on a date in the past or future?
Yes. Change the "age on this date" box to any date — useful for school admission cut-off dates, job applications, exam eligibility or pension dates.
Why is my age in hours only approximate?
It multiplies whole days by 24, so it ignores your time of birth and daylight-saving clock changes. Years, months and days are exact.
What day of the week was I born?
The results show the weekday of your date of birth, worked out from the calendar for that exact date.
Sources
Formulas last reviewed: September 30, 2026 ·How we check our formulas