Age Calculator
Find your exact age in years, months and days — plus total weeks, days and hours.
Content updated July 31, 2026
Your age is calculated as of today, September 10, 2026.
How old are you exactly, right down to the day? This age calculator takes your date of birth and works out your precise age in years, months and days as of today — along with fun totals like how many days, weeks and hours you've been alive.
It handles leap years and varying month lengths correctly, so the result is accurate rather than a rough estimate.
The Age formula
Age = today − date of birth, expressed as full years, then remaining months, then leftover daystoday = the current date · date of birth = your birthday. Years are counted first, then whole months, then the days left over — borrowing from the previous month where needed, exactly as you would by hand.
Worked example
For a birth date of 15 March 1990 evaluated on 29 July 2026, that's 36 full years, plus 4 months and 14 days — or about 13,285 days in total.
Assumptions, rounding, and limitations
Assumptions
- Dates are interpreted as local calendar dates, not UTC timestamps.
- Age is measured from the birth date to the current local date.
- A 29 February anniversary clamps to the last day of February in a non-leap year.
Rounding: Years, months, days, weeks, and hours are reported as whole elapsed units; partial weeks are truncated.
Limitations
- Hours are calendar-day totals multiplied by 24, not elapsed clock hours across daylight-saving changes.
- The calculator does not accept a separate as-of date.
How your age is calculated
The calculator counts the full years, then the remaining months, then the leftover days from your birth date to today, borrowing days from the previous month where needed — exactly how you'd count it by hand, but without the errors.
The totals (months, weeks, days, hours) are derived from the exact number of days between the two dates, so they account for leap years automatically.
Frequently asked questions
▶How do I calculate my exact age?
Count the complete years from your birth date to today, then the extra months and days. This calculator does it precisely, including leap years.
▶How many days old am I?
It's the total number of days between your date of birth and today, leap years included. Enter your birth date above and the calculator shows your age in days, weeks and hours.
▶Does the calculator handle leap years correctly?
Yes. It counts the real number of days between the two dates, so 29 February and varying month lengths are all accounted for automatically.
▶Why is my age in months not just my years times 12?
Because of the leftover days. Full months are counted from your birth date to today, so someone aged 30 years and 5 months is 365 months old, not simply 360.
▶Can I use it to find someone's age on a past or future date?
This tool measures age as of today. To find the gap to any other date, the date difference calculator lets you set both the start and end date.
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Open calculator →Disclaimer: Age Calculator results are estimates for general information and education only, and are not financial, tax, legal or medical advice. Verify important decisions with a qualified professional.