About this age calculator
Your age in years, months, and days is counted the way people usually say it: whole years since your last birthday, then whole months since the last monthly anniversary, then the days left over. Because months have different lengths, this cannot be found by simply dividing the number of days. The calculator counts calendar months and handles leap years, and someone born on 29 February has their birthday on 28 February in common years. Totals in weeks, days, hours, minutes, and seconds count whole days from the date of birth, so they do not depend on the time of birth or on your time zone. Everything is calculated in your browser.
How to calculate your age
- Enter your date of birth. Pick the date with the calendar or type it, or press an example.
- Choose the date to measure to. Leave today’s date to get your current age, or pick a past or future date to find your age on that day.
- Press Calculate age. Read your exact age, the totals, the countdown to your next birthday, and the milestones you have passed and those coming up.
Frequently asked questions
How is age in years, months, and days calculated?
Whole years are counted up to your last birthday, then whole months up to the last date with the same day number, and the remaining days are added. Someone born on 15 June 1995 is 31 years, 3 months, and 19 days old on 4 October 2026.
When does someone born on 29 February have a birthday?
In leap years on 29 February, and in other years on 28 February, which is when most legal systems count the new age. The calculator follows that rule for birthdays and milestones.
Can I calculate an age on a past or future date?
Yes. Change the second date to any day after the date of birth, for example to see how old someone was on a historical date or will be on a wedding day.
Why are hours and seconds whole-day totals?
The calculator works with dates, not times of day, so it counts from midnight to midnight. If you were born in the afternoon, your true age in hours is a few hours less.
What are day-count milestones?
They are birthdays measured in days rather than years. Turning 10,000 days old happens at about 27 years and 4 months, and some people celebrate it as a special day.