Your exact age, down to the day
Pick a date of birth and this calculator breaks the elapsed time into completed years, months and days — the way age is normally expressed — and also totals it in months, weeks and days for the curious. By default it measures up to today, but you can set any target date to find an age in the past or future.
How the calculation works
Rather than dividing by an "average" year, the tool walks the real calendar: it counts full years first, then the leftover full months, then the remaining days, borrowing from the previous month where needed. Because it uses actual dates, leap years and the different lengths of each month are handled correctly, so the result is exact — not an approximation.
Handy for more than birthdays
- Check eligibility that depends on a precise age or anniversary.
- Work out how long ago an event happened, or how far away one is.
- Find someone's age on a specific date — a wedding, a milestone, a deadline.
Frequently asked questions
How does the age calculator work?
It compares the date of birth you enter with a target date (today by default) and counts the completed years, then the remaining months, then the remaining days, accounting for different month lengths and leap years.
Can I calculate age on a future or past date?
Yes. Change the "age at" date to any date to find how old someone was, or will be, on that day.
Does it account for leap years?
Yes. The calculation uses real calendar dates, so leap years and varying month lengths are handled automatically.